Put trailer on towbar but lights dont work - Cars & Trucks

if you have the proper kit , the it is a simple matter of pulling the harness connector from a tail light assemble and inserting the harness on to the assembly the fitting the harness back on to it
the wires are color coded and all new trailer plug connections have the pin numbers for the color wire to get the correct lights working at the back
if you are not power or circuit savvy then get the towbar shop to wire it up or get an auto electrician to do the job

Yes you can tap into the wiring loom for trailer lights, that is how rental agencies do it on their trailers.

The answer to this question depends on several factors such as: Whether the towbar was a factory fitted unit fitted during
pre-delivery, a genuine brand unit or an aftermarket unit & who, where & when it was fitted...
The majority of towbars & the assosiated wiring out there are simply wired in to the rear tail light circuits such as:

• Trailer stop lights wired to vehicle stop light circuit in eighther of the rear tail lights.
• Trailer park lights wired to vehicle park light circuit same side as the stop lights, as above.
• Trailer number plate lights wired to vehicle park light circuit same side, as above.
• Trailer reverse lights (if fitted) wired to vehicle reverse light circuit same side, as above.
• Trailer left hand indicator wired to vehicle left hand indicator light circuit
• Trailer right hand indicator wired to vehicle right hand indicator light circuit.

This means that if fitted in this manner (as the majority are) the corrosponding vehicle light fuse will affect the trailer lights unless the is an inline fuse fitted to each single circuit (which cld be blown). This is very uncommon & wld be a costly way to do it...

In some more modern cars that came from the factory (not the dealership ie. pre-delivery) with the tow bar fitted as standard equipment it is possible that there cld be a sepparate little fuse box or section in the main fuse box (the position of the fuse box/es shld be in your owners manual usually Under the bonnet, under the dash or behind font foot kick panels, & if you dont have an owners manual for your vehicle they are usually available to buy an aftermarket version or these days on the internet & often downloadable for free or @ a small charge).

All the best & I hope this is of some help...


Referances: Me, I am an auto mechanic.

Towbars are fairly simple, if the towbar fits the frame, you are all set, if it doesn't, you have the wrong one. If there are holes that line up, use them, if not, you can drill through the frame very easily, it is soft steel, Put some bolts in there that go through about 1/2 longer than the frame parts. Support the towbar with a jack, make sure it stays put. Drill a small pilot hole first with about 1/4 inch bit, then go to the hole size of the towbar, 1/2 inch. Those step bits work great, put in the bolts, tighten them up, all set. As far as positioning this thing, I would make the ball stick out just past the bumper, if no hole line up. You don't want to be smashing the trailer into the bumper all the time, so make sure it is enough, but not so much that you trip over it. Hope this helps.

you need to have a trailer module (TRM) installed before you hookup a trailer. you can go to a volvo dealership to have this done

You will have to get a factory approved kit . Any modification to the lighting system will interfere with the Bulb faifure warning as the wattages and resistances will be altered outside the normal Jaguar settings. There is designated kits for these types of electrical systems from quality tow bar makers .......

The best, and in fact the only recommended solution is to use a plug-in dedicated wiring kit for this car, it plugs into a grey connector on the chassis on the rear of the left hand side. this is the connector that the cars rear light loom is plugged into and the towbar loom piggybacks onto this using the same watertight sealed connectors. There is a trailer indicator warning light already built into the dash display so no need for any other monitoring of the trailer functions. This wiring kit should cost you around £40-£50 and will only take around 10mins to fit. The other alternative is to solder the towbar wires to the cars loom, but this is time consuming and may invalidate the vehicles warranty.

Hi Paul,

This should help,

Plug Types/Application
7 Way - RV Trailers, Horse and Utility Trailers
6 Way - Horse, Stock and Utility
4 Way - Utility Trailers

Columns are Color, Function, Mark on the plug.

Seven wire Trailer plugs:

Horse, stock or utility trailers:
White = Ground - 1
Blue = Electric Brakes - 2
Brown = Tail and clearance lights - 3
Black = Battery, aux power - 4
Yellow = Left turn/Brake - 5
Green = Right turn Brake - 6
Orange or Purple (not both) = Auxilliary or Reverse - 7

Recreational Vehicle:
White = Ground - 1
Blue = Electric Brakes - 2
Green = Tail and clearance lights - 3
Black = Battery, aux power - 4
Red = Left turn/Brake - 5
Brown = Right turn Brake - 6
Yellow = Auxilliary or Reverse - 7


Six wire trailer plugs:

Horse, stock or utility trailers:
White = Ground - GD
Yellow = Left turn/Brake -LT
Green = Right turn Brake -RT
Brown = Tail and clearance lights - TM
Red or Black (not both) = Battery, aux power - A
Blue = Electric Brakes - S

Recreational Vehicle: (color, use, plug mark)
White = Ground - GD
Brown = Right turn Brake - RT
Green = Tail and clearance lights -TM
Black = Battery, aux power - A
Red = Left turn/Brake - LT
Blue = Electric Brakes - S


Four wire plugs:
White = Ground
Yellow = Left turn/Brake
Green = Right turn Brake
Brown = Tail and clearance lights


Ground should be 10ga.
Others 14 ga

Best regards
Mike

the best way to wire it is to get a tail gate board off a trailer and plug it in to the towbar then wire red to stop n tail lights green or yellow to the earth what other orange or brown to indicator sum wires may differ in colur wat colour wires do u have on the towbar

Behind the left reversing light is a grommet that you can put the towbar wire through, and just behind this is a large black connector, this has all the wires for the towbar, unfortunately there are several wires of the same colour that do different things, best use a test lamp on each one as you connect them. The indicators are "self monitoring" so you do not need a buzzer or light on the dash to tell you that the trailer is working, when you indicate with the trailer connected the ticking sound of the indicators changes to a pinging sound.