Post by Chuck on Jan 17, 2018 14:23:30 GMT -5
Very Important !!!!!
A STARTING POINT -
Take a notepad an some painters blue tape along with a black thick marker pen when doing your PDIThis list is for new or used 5th wheels an for the most part but it also in many case's applies to Travel Trailers (TT)....
I may have missed some things, let me know an I will add every so often an re-post or edit this post:)
Other Items Needed
1. A flashlight with a strong beam is a very useful tool to have.
2. A screwdriver with a straight, Philips and square bits will come in handy as well.
3. You should also have available the delivery invoice for the trailer.
Note: An invoice will show all the standard equipment and ordered options and should be compared to what you
3. You should also have available the delivery invoice for the trailer.
Note: An invoice will show all the standard equipment and ordered options and should be compared to what you
thought you ordered and should be referred to during your inspection.
4. Pictures from the glossy brochure will also help in your inspection.
Note: You will need the understanding & cooperation of your dealer for this process, as it probably involves far
4. Pictures from the glossy brochure will also help in your inspection.
Note: You will need the understanding & cooperation of your dealer for this process, as it probably involves far
more depth & detail than they normally anticipate and schedule for.
Note: Make sure they know about it in advance. (You may get a better-prepared trailer if you do!)
At the very least, tell the person doing the "owner inspection" or "walk through" what you intend to do, give him
Note: Make sure they know about it in advance. (You may get a better-prepared trailer if you do!)
At the very least, tell the person doing the "owner inspection" or "walk through" what you intend to do, give him
or her a copy of this checklist and work with them to plan the time accordingly.
5. Above all A sense of humor will also come in handy!
6. Finally, my assumption for this PDI is that both (if fitted) propane tanks are full, shore power is available,
6. Finally, my assumption for this PDI is that both (if fitted) propane tanks are full, shore power is available,
city water and a hose are located close by and sewer connections, a drain or a dump station is available.
A fully charged battery must be connected as well.
7. Bring a level to check the level of the trailer
8. Ask that all manuals for your trailer are available an have them show you each manual when testing
each an every appliance, leveling jacks, TV, even the toaster if the trailers has one ... If no manual do
not except we will get you one, tell them it should have come with the trailer from MFG an to produce
one before you sign on the dotted line !!!!!
Safe Travels
Chuck
Let me add something before you read the list, an I as other will tell you, your dealer is the most an I mean the most
important part of buying your RV... Bad dealer, bad service, make sure your dealer will honor your warranty to it's
fullest, do not let them BS You, ask them how far out you will be told if you need service or warranty work ...
If they tell you no problem just bring it in an we will fix it, they are full of Bull !!!! During the summer an early spring
it may take weeks to months to get in for any type of service work as you will read again below
WARNING !!!!!
Do not sign anything or give dealer any money other than a small down payment before doing your PDI, if you
sign an pay for trailer before hand you now have no bargaining power as far as things that you find wrong during your PDI !!!
Ninety eight percent of dealers will do paperwork after your PDI is done along with repairs are in progress, but there are
the two percent that want money an paperwork up front... To me these are not to be trusted an for the most part I
myself would walk away from the sale no matter how good it is ...
Most dealer's during the winter will be at times two or three weeks out, in the spring after the end of part of February
or early March you may be looking at 2 or 3 months depending on how many brands of trailers they sell an how big of
a dealer they are.
Big dealerships, sometimes may mean slow, an little dealerships may be quick to repair but not all the time. Example our
selling dealer stated that it would be two months or more when we had a furnace problem a month after we bought the
trailer, called the furnace company they sent us to another RV dealer who was smaller an sold a different brands, furnace
was fixed in a week...
So I can't say it enough, make sure you have a good dealer, an do not let slick willy BS you into thinking they
are great when they are not even close ...
Safe Travels
Chuck & Hildi
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(On the outside)
1. Look down the side of the unit to check for bumps or depressions in the siding.
Divide each side of the unit into 2, 3 or 4 sections and inspect for siding issues: color variations, dents
or irregularities. Do the same for the ends of the unit Look at places where vinyl film is used for graphics
to make sure it is free of any air bubbles. Check ends of any decals for uniformity or "mistakes" that
may have gouged the siding. Look closely where masking tape was used for paint graphics to make sure
there is no over-spray.Carefully check for surface smoothness and any place when paint coverage is
marginal or where there are bubbles. Any problems can be verified and corrected at this point with a
lot less hassle.
2. look directly at the wheels (if tandem axle)kneeing in front of them at about 4ft away an looking
toward the rear, thus if an axle is bent you will see that the tires will be out of line, cockeyed to one
another ... If single axles put a level on the top of the axle in the center ...
2. Look at date on tires an make sure they are current within the year you are buying the trailer
(When I say current I mean within 5 or 6 months not years), if over a year ask them to replace such
an do not take we can't for an answer, they can they just don't want to spend the extra money !!!!
NOTE: If your buying a used trailer from other than a dealer used tires over a year old that have
been sitting can be a bargaining tool, if over two years old they will need to be changed if sitting
for that long an should be used as a bargaining chip do to the fact they need to be changed before
you travel an distance ...
3. Open an close door latches to the storage area's to make sure they close an open easy, you should
not have to tug hard on a latch handle when doing such, check to make sure the seals around the
storage doors are not falling off or down or missing gasket used on all doors for proper adhesive and
coverage.... As well all hinges should be tight and secure and the an as stated before all latches should
hold the door tightly closed and still be easy to open. Feel the floor or carpeting and look for any
signs of moisture that might indicate rain leakage... Verify that compartment lighting (if fitted) works
properly. Any gas cylinders used for keeping the door open should be properly installed so as not to
interfere with items stored in the compartment. If clamp-type door hold-opens are used, make sure
they are present and hold the door correctly.
4. Entry Doors - check the gasket used on all doors for proper adhesive and coverage.
Look closely at the door from the inside and confirm that it sits flush against the inside of the
Look closely at the door from the inside and confirm that it sits flush against the inside of the
doorjamb. Confirm that each key works in the appropriate lock.
The main door should open & close smoothly and lock with out undue effort.
Check that the screen door opens smoothly alone and locks to the main door without any extra effort.
The main door should open & close smoothly and lock with out undue effort.
Check that the screen door opens smoothly alone and locks to the main door without any extra effort.
5. Windows - check closely around each window to make sure it has been properly aligned and sealed.
6.Slide Out Operation - If your RV includes a slide-out or slide-outs then spend the time it takes to
understand its operation.
Start by checking the seals while the slide is retracted/closed.
You should not be able to find any places where you can see light or detect airflow.
Use a flashlight to look into dark corners.
Understand the mechanism that extends and retracts the slide.
Operate it several times and understand any restrictions on operation.
Understand the manual retraction process and actually perform the retraction as if the automatic
Start by checking the seals while the slide is retracted/closed.
You should not be able to find any places where you can see light or detect airflow.
Use a flashlight to look into dark corners.
Understand the mechanism that extends and retracts the slide.
Operate it several times and understand any restrictions on operation.
Understand the manual retraction process and actually perform the retraction as if the automatic
mechanism had failed.
Look for proper alignment of any wheels that may ride on carpet or other flooring, to insure proper
Look for proper alignment of any wheels that may ride on carpet or other flooring, to insure proper
clearance. Understand any locking mechanisms that are used to hold the top of the slide out tight
against the top of the RV.
Do your best to make sure the seals are properly installed and operational when the slide is retracted
Do your best to make sure the seals are properly installed and operational when the slide is retracted
and also when it is extended.
Look under the slide to make sure slide guides are in place an not pulled from the inside wall of the
trailer when opened or closed ...
Check to make sure the underside of the slide has no rips or metal showing or hanging down to
impend it's travels ...
Check the under-slide area for proper routing of wires or cables.
Confirm that nothing rubs on the tires (parts of the slide, wiring, insulation, Etc.) when the slide is
Confirm that nothing rubs on the tires (parts of the slide, wiring, insulation, Etc.) when the slide is
retracted.
Important Note: Check to make sure that the condensation drain hose is coming out the bottom of
the slide, if RV Tech sates they do not know ask for someone that can show you such ... This is
very important because if the drain, drains into the bottom of the floor an not out the bottom of
slide it can cause water damage to the floor an a expensive repair in the thousands of dollars ...
anything else until you are sure you know how your water system functions (take notes) ...
8. Make sure tech or if used the owners show you how to operate the hot water system works, including
the black or possible a red rocker switch on the hot water tank ( it must be on to have hot water )...
9. Sewer & Fresh Water Connections - Inspect this area on the trailer to make sure that nothing is
broken or deformed. If appropriate at this time, make certain you understand how each valve or fitting
works. Understand the proper function of the black and gray water valves, make them explain which
is which an do not move on till you are sure you know of each)...take note's or video the operation!!
If tank flushing is installed, understand how it operates. Understand where the low point drains are for
If tank flushing is installed, understand how it operates. Understand where the low point drains are for
the fresh water system.
NOTE: make sure you understand what sinks, shower, dishwasher empty into what tank, if RV Tech
states he/she dozen't know tell them to find someone that knows !!! this could be a deal buster
10. Telephone & Cable TV Connections- Find and understand the telephone and cable connections.
Make sure a weather cap is present for each connector and that connectors are properly identified &
Make sure a weather cap is present for each connector and that connectors are properly identified &
mounting plates are properly sealed.
11. When the tech is or if used the owners explaining the leveling system in detail, do not let them (tech)
operate the system ask them to let you do it (sort of a hands on). Both the husband or wife should operate
the leveling system till you are happy you know how it works period ...
Take note's or video the operation!!!!!!!!!!
Note: Bring a level, check the level of the trailer once setup an the LCI auto level states the trailer is level
using the auto leveling. If trailer is not level then ask the Tech to zero the leveling system using the LCI
manual ...take note's or video the operation!!!!!!
using the auto leveling. If trailer is not level then ask the Tech to zero the leveling system using the LCI
manual ...take note's or video the operation!!!!!!
Note: Do not let them rush you on the operating of your leveling system, take note's or video the
operation of such because you will forget, trust me !!!!! Again take many note's or video the
operation it is not a complex system but there are tricks to it you need to know !!!
12. If you have the One touch control by LCI open an close an open the slides multiple times before going
into the trailer so you know how to operate such an make sure they are opening an closing all the way an
operating correctly ... Walk around your trailer an go inside your trailer to check that the slides are defiantly
open all the way !!! ...
Note: If your trailer has a APP
Make sure they show you the APP if there is one for your trailer to operate the leveling system an let them load
it on your phone an make sure it works if there is one. Make Sure you both of you know how it works by both
opening an close slides, lights, awnings multiple times till you are both happy you know how it works !!!!
take note's or video the operation
13. Ask how to open/close slides in an emergency, make them show you how an don't let them say this
is how you do it, SHOW ME !!!
14. Propane -If the tank(s) are contained in a compartment, there should be no possible way for propane to
enter into the RV or any other compartment.
Understand how the regulator works and how it switches between cylinders.
Confirm that a leak test has been performed on both pigtails between the tanks and regulator and the rest
Understand how the regulator works and how it switches between cylinders.
Confirm that a leak test has been performed on both pigtails between the tanks and regulator and the rest
of the system. Locate and understand the operation of the main shut off valve (if any)
15. Outside look under for any opening to the outside that critters can find a way in...
(front leveling legs on mine were not sealed - open to basement and then openings to
interior from that space)
(front leveling legs on mine were not sealed - open to basement and then openings to
interior from that space)
16. Make the tech or if used the owners show you how to extend an retract all awnings, make sure
there is no cut's, holes etc in the awnings while extended. (make sure they show you an let you
operate all the switches for the awnings an make sure they show you how to operate the LED lights
in the awning) take note's or video the operation
17. Ask for a creeper an make sure that all the panels under the trailer a secure an not hanging down ..
Note: you will need the creeping later on when checking under trailer while water is running inside into
sinks to see if the is any water leaks underneath the trailer...
Note: If panels are hanging down ask why, is there a reason, push on panels to make sure they are not
full of water ow wet ...
full of water ow wet ...
Note: While under trailer have tech or if used the owners show you what the drain tubes functions are an
what they go to ...
18. Do not let them winterize your trailer before you get there to do your PDI, if at the end of
the camping season in your area have them winterize your trailer after you do your PDI ...
Note: If buying from a dealer they should not charge you to winterize your trailer after a PDI, this
should be an automatic function as a perk for buying such used or new either one...
If you a privite owner more than likely you will be on your own to winterize the trailer if you buy such ...
Note: even when buying from a dealer or private owner ask to have them show you how to winterize
your trailer after your PDI, this includes winterizing the dish washer if you have one ....
19. If winterized before leaving the dealer make sure fresh water an hot water tanks are empty ! !
Note: Make sure the tech shows you were the drains are for both(See number 15) !!!
20. Make Tech or if used the owners show you how your propane system works an how to exchange
tanks, also check to make sure that propane hose's are tight an no leaks from such ...
NOTE: Ask RV tech or if used the owners to spray soapy water on all propane connections
(DO Not Take I don't have any or NO that takes to long or I have already done that,
say show me)
21. Battery - Check the battery box to verify that it is ventilated and that any compartment
slide mechanisms work properly. Verify that no battery cables are rubbing on any part of the
frame because that will eventually end up with a short circuit and possible fire.
Understand the battery type provided and how to maintain them, an make sure the
Understand the battery type provided and how to maintain them, an make sure the
batteries are not dead, ask to replace them if they are over a year old !!!
22. Make sure ladder on the back of trailer is solid an have tech show you how to raise an lower the
bottom of the ladder if it's a two part ladder ...
Note: If a TT make sure ladder is solid if no ladder ask why an is it safe for anyone to be on trailer roof ..
22. Make sure ladder on the back of trailer is solid an have tech show you how to raise an lower the
bottom of the ladder if it's a two part ladder ...
Note: If a TT make sure ladder is solid if no ladder ask why an is it safe for anyone to be on trailer roof ..
23. If your spare is under your trailer, ask how do you get it down, show me how, were is the tool/crank
to do such !!!
Note: Again asking how to lower your spare if it is underneath your trailer you are then assured that you have
a tool/crank to lower spare if needed, don't take it will take to long, have them show you !!!
24. If outside Kitchen check to make sure refrigerator is working an is cooling an again check for a
condensation drain hose, see if there is one an is it coming out the bottom ofthe slide
25. If outside kitchen has stove make sure all burners work or if having to add propane bottle were to
hook such up.. If stove is hooked into propane system of trailer were is shut off valve is for such ...
26. On outside kitchen see where sink drains are, if any, do they empty into trailer gay tank or like some
you have to put a five gallon buck under sink drain, ask an make sure you know !!!
27. Roof Sealing & Fixtures- You will need to get up on the roof here, so round up a ladder or carefully inspect
the one on the back of the unit if you are going to use it. Check that all the mounting points are solidly attached
to the body and the rungs are firmly fixed to the frame.
Climb on the roof and inspect all seams, gaskets and any other place that the roof material has been cut
or holes drilled. Check that all shrouds & covers are intact, unbroken and properly seated on the roof.
Note: Proper polyurethane caulking should have been used to seal all places where the roof has been penetrated.
Check closely around air conditioners, vents, antennas, sewer vents, and side seams. Look for any signs of
Check closely around air conditioners, vents, antennas, sewer vents, and side seams. Look for any signs of
bubbles (large and small), delamination, foreign objects or protruding screw or nail heads under the
membrane (if a rubber roof).
30. Check dates on all tires an make sure they are at least 6 months or newer, if over a year old ask to have
them replaced !!!
31. Ask RV Tech to show you how to reposition your awning to different levels other than straight out ...
Inside the trailer (slides open)
IMPORTANT NOTE: After your slides have been open an you have tested everything making sure
that the refrigerator an stove work on electric an propane have the tech close an open the
slides a check to make sure refrigerator an stove work on electric an propane again ...
There have been reports of the refrigerator an stove not working on propane after slide was
closed an re-opened ...
1. Check all walls for any bubbles or loose or water damage along with ceilings (brown spots may
mean water damage)...
2. Check all trim that it's not loose or falling off or screws hanging out
3. Check all lights to make they are working including awning lights an again were all switches are...
Note: if tech dozen't know what a switch is or it function have him or her find someone who knows
what that switches function is, Do not take I do not know but I'll call you later with the answer,
say I'll wait till you find someone now while we are hear !! )
take note's or video the operation
NOTE: If your dinning room table doubles as a bed make them show you how to to arrange the
cushions into a bed, (don't let them say it's easy to do) make them show you so you know everything
is there an the cushions fit correctly ... take note's or video the operation
5. Check floor for softness or loose, walk thought the complete trailer, not stomping but pushing down
to make sure there are no loose boards or soft spots ...
Note: In the bedroom of some but not all Durango Gold 5th wheels the bedroom floor has not
been screwed down properly near the closet ...
6. While in bedroom check under mattress that all screws are in the hinge an that the small
hydraulic rams holding the bed up are attached firmly ie glued an screwed ...
7. Have tech or if used the owners show you the slide assembly under the bed an how to get to the
motor an slide rails, while under the bed make sure the two folding chairs are there if your trailer calls
for four chairs at the dinning room table take note's or video the operation ....
NOTE: Note all Durango golds will have folding chairs under the bed, it depends on the model,
if you have four chairs already at dinnering room table you will more than likely not have any under bed ...
8. Check the seals on the slides that they are against the wall an the slode is fully open an sealed tightly,
you should not be able to put your hand nor fingers between slide seal an wall, if you can it's not opened
all the way...
9. Have the tech or if used the owner slightly close each slide an inspect the inside slide seal for rips,
holes etc ...
10. Check all cabinet doors that they will open, close, an are straight an not have loose hinges ...
11. Check all cabinet's that if shelf's are suppose to be there that in fact they are ...
12. Have tech or if used the owner show you how to operate dinning room table an if it has a leaf or
can be pulled away from wall an then turned to seat four people ...
NOTE: Some dinning room tables will have a pull pin under the table to be able to pull the table
away from the wall an turn the table for use... This is a pull down type of pin, make sure it is there
an is working properly ... This pull pin has been known to come loose an drop out, make sure it is
screwed in tightly, if not not tight just screw it back in
NOTE: See above for making such into a bed if your dinning table doubles as such ...13. Make sure if there is sink covers for the kitchen sink that they are there, if not in sink look in the
sink cabinet for such ...
14. Make sure all water pipes are connected under all sinks an tight, have tech pull on them
while you look on while water is running ...
Note: If there is any leaks you should now also see such do to the fact you had the RV Tech
run water thought your system when inspecting the underside of the trailer for leaks now has
water running while pulling on pipes to make sure they are tight an no leaks ...
Next an after running water test: Fill the sink and let water stand after you have inspected
that the pipes an they are tight, thus now you are checking to make sure the sink drain or sink
has no leaks as well ...
15. Have tech or if used the owner turn on the hot water an make sure you get hot on both electric
an propane, don't take no for an answer if he or she states we can do that right now because there
is no water, tell them to put water in the unit so you can test it.
16. Have tech or if used the owners show multiple times how to operate the Tv or Tv's if you have
two both on cable an on the trailer antenna an where the amplifier switch is for the TV's, if they do
not know where or how tell them to find someone who can tell you ...
take note's or video the operation!!!
NOTE a: Make sure you have remote controls for either one or both TV's an use them to make sure
they work !!!!!!!!!!!!!!
NOTE b: Check that both TV's receive properly on Cables as well as on what is called Air (ie ourside
antenna)...
NOTE c: There have been bad boosters found as well as bad or loose cable ends on some system's
antenna)...
NOTE c: There have been bad boosters found as well as bad or loose cable ends on some system's
NOTE d: Have Tech or owner if used show you how the Satellite system works if the trailer has
one no matter if you are not buying or going to have a Satellite system take note's or video the
operation!!!
Note E: "Ask salesman or RV Tec to show you how to operate TV doing a Channel scan"
"Ask salesman or RV Tec to show you how to operate TV Booster an it's location"
"Ask salesman or RV Tec to show you how to operate TV Booster an it's location"
17. Have Tech or if used the owner show you how to work the fireplace an make sure you have
remote control for such an make sure it works !!!!!!!!!!!! take note's or video the operation
18. Check closest an pantry shelf's an make sure it is tight against wall's if there are such...
20. Check all draw slide to make sure they are tight in the bedroom an also kitchen an living
area...
21. Make sure that the air conditioner or conditioners if two both work an blow cold air an how
to turn them on an off ... take note's or video the operation
22. Check all heat ducts blow air (in some case's ducts have found to be off the furnace an need
to be reattached)
23. Make sure heater heats trailer to a comfortable room temperature, check heater will work
on propane as well as electric...
24. If you have solar charge port ask tech to show you the wiring locations an ask to have a
panel hooked up to see that the panel will work !!!! take note's or video the operation
25. Check all emergency exit windows, that they are correctly fastened an will not fall off when
opened, open an close these emergency windows a number of times to make sure !!!
26. Open an close all windows a number of times to make sure every window that works,
it works smoothly with no sticking !!!!
27. Have Tech or if used the owner show youwWere are fuses/circuit breakers located and
insure they are marked, most seem to have a "main" fuse or breaker from the batteries,
(where is it an is it fuse or resetting breaker )
NOTE: Ask for spare fuse's especially for the main fuse - it goes and you loose all 12V !!!!
NOTE: Ask for spare fuse's especially for the main fuse - it goes and you loose all 12V !!!!
28. Basically if it opens or moves, try it, operate all systems from lights inside & out to fridge,
stove, oven, micro wave, TV(s), stereo system, vacuum system, 110 outlets, 12V outlets,
fireplaces etc.
stove, oven, micro wave, TV(s), stereo system, vacuum system, 110 outlets, 12V outlets,
fireplaces etc.
29. Take your time, the shortest your PDI should take is at least 4 hours, do not let them rush
you. Remember when you pull off the lot it's yours an getting back into the dealer may take
weeks if not months !!!. So make them fix any an everything before you sign or give them any
major money, if they say they can't till you have sign the paperwork tell them then you will just
have to look elsewhere for a trailer ...
5th Wheels
1. Make sure you have the right weight hitch for your trailer, rule of thumb is an average of 2k above
what the total weight of your trailer is, ie 14k the last you should have is 16K hitch ...
2. Make sure your trailer is level when hooked up to your truck, average height for a 5th
wheel should be 6 to 7 inches from bed rail to bottom of the trailer when hooked. For TT
the trailer should be level as much as possible but your tow vehicle may have a slit sag
in the rear but not very much an should be as close level with your TT as possible ...
3. Make sure the proper type electrical cord from your 5th wheel to the camper has the correct plug
an test it by plugging in your trailer to your truck once hooked up even before raising you landing
feet/gear ...
Note: Make sure your electrical cord is not hanging down to the point it will catch on something
going down the road, if to long have the dealer shorten the cord but not to the point you can't make
a ninety degree turn when backing up ...
Add Note: Some but not all pickup trucks have the trailer plug in the bed of the truck, thus your
electrical cord or what is called a pig tail could be shortened up to the point it is not hanging
outside you truck ...But again make sure it is long enough that you can make sharp turns
while backing up an it will not catch on anything in the truck bed ...
4. Check all marker lights to make sure they are on along with turn signals are working by using your
four way flashers
Note: You might be able to check lights without hooking up to trailer an only back up to it but in
some but not all case's you need to be grounded to the truck or tow vehicle to complete the ground
from truck to trailer so lights will work ...Again this is not in all cases but it's just a good idea to
hook up to the trailer to make sure ...
5. Before rising the landing gear make sure your 5th wheel hitch is locked an pull against the trailer
while holding the trailer brake on !! There are two reasons for this one you should always check to make
sure you are hooked to trailer while langing gear is down so you will not drop trailer on the bed of your
truck ... The second is to make sure you are solidly hooked to trailer ....
6. Hitch and unhitch if at all possible numinous times to get use to such if this is your 1st 5th wheel or
you have switched 5th wheel hitches an or new to the LCI operation ....
Note: lately there seems to be a high learning curve on the LCI system on how to operate such for the
front landing legs even for the seasined RV 5th wheel owners ...
Hooking up to your (Travel Trailer) (TT)
1. Make sure you have the ball an right hitch weight disputation hitch for your trailer ...
2. Make sure your trailer is level when hooked up to your truck, For TT the trailer should be like a
5th wheel level as much as possible but your tow vehicle may have a slit sag
in the rear but not very much an should be as close level with your Tow vehicle as possible ...
3. Make sure the proper type electrical cord from your trailer to the camper has the correct plug
an test it by plugging in your trailer to your truck once hooked up even before raising the landing
gear ...
Note: Make sure your electrical cord is not hanging down to the point it will catch on something
going down the road, if to long have the dealer shorten the cord but not to the point you can;t make
a ninety degree turn when backing up ...
4. Check all marker lights to make sure they are on along with turn signals are working by using your
four way flashers
Note: You might be able to check lights without hooking up to trailer an only back up to it but in
some but not all case's you need to be grounded to the truck or tow vehicle to complete the ground
from truck to trailer so lights will work