7 pin parking light fault

[drover]

Got a curly one here, the 2015 WK2 has the Jeep tow pack harness fitted, when plugging in the 7 pin from van the brake and turn sigs all working fine but the clearance/park lights on van won't come on and on the Jeep the RH rear parker goes out, all the others work.

Did a circuit test uncoupled and pin on Jeep is live with parkers on, jeep lights all good and using another power source for van and all its clearence lights work, just plug into Jeep and nothing.

About to start pulling things apart to track and test wiring but only thought I have is the computer for some reason see's too much power for tail light so shuts it down even though my circuit diagram shows the tow harness and tail light not related..

Got me stumped and I don't want to have to pull panels or pop those stupid plastic rivets........

[Mudgee hunter]

Trailer have leds?
Test trailer lights with voltage to lights etc, ground using neg at pin.
Test corresponding pins ground + yellow etc using a bridge wire ( to eliminate a bad connection between plugs)

[drover]

Yep, tested each unit seperatley and van loom and I have found the cause.

The Jeep is more sensitive to voltage draw than I thought, tested it on boat trailer everything worked fine.
Hooked my Hi Lux up to van everything worked fine, separate power to the van clearance lights everything worked with very little voltage drop from start to end of loom, the plug checked out okay but soon as clearance lights turned on no power from Jeep..... even plugged an array of 250 leds to it, worked fine.

Only thing I could think of was the Jeep didn't like something so I pulled out all the van clearance lights, unplugged them bench tested each one and they all worked fine, then plugged Jeep into van with Jeep parkers turned on, they stayed on, so not the wiring, so one by one connected a van light till I found some that shut down the Jeep lights, tried them with less lights connected and they still failed so came to the conclusion that they had some anomaly that the Jeep didn't like but otherwise worked okay..

12mths ago the van had hail damage repaired and each light that failed was one removed by the repairer but since they all worked with the Hi Lux and Colorado hooked up I can only surmise the Jeep is more selective.............

The old start at the beginning method, having a variety of testing options helped narrow things down and thankfully it wasn't a big time Jeep Thing interesting to know though.

[wrench]

Hi Drover, we’ve just repaired a 2014 that had the Jeep? wiring package without a trailer module so all the trailer power was coming thru the body module and was throwing codes and well as tripping out. If there is no independent power supply back to the battery for the trailer wiring then rewire it with an aftermarket module. This one was also setting a code for the LHR brake light which was due to an original Redarc controller incorrectly wired to the LHR brake light.
Just lift the rear panel and spare tyre tub to check. You might have to take the LH inner quarter panel if rewirng is required.
Cheers

[russell w]

Drover, had same problem when going from 12 build to 15 build with the same caravan. I fitted relays to the tail lights and the stoplights, as they will fail and no van brakes had to use the controller over ride. Turning the motor off and back on will get the stop lights and brakes going again for a while. I tried LED lights but not really successful . I actually had to fit 2 relays for the stop lights one for the brake controller and one for the lights and electric brakes. Regards Russell

[drover]

Well I made an interesting discovery in that the van lights were T10 globes not led's as I thought, from outside look like led's even the wires but when I cracked one apart bingo a globe, so have ordered T10 leds as replacements, hoping they keep the Jeep happy..... other units I have got from same mob ran well so hope these do as well but I think the globes were the problem.

Interesting to hear about your experience @russell w, to date only the clearance lights have given problem, the rest working correctly.

Tracked the tow harness and its genuine and plugs into the wiring loom and I tapped into the connector off it for the brake controller

[drover]

Fitted T10 led's to all the lights and all working well, brighter and the Jeep is happy.