Leaving for a long weekend tomorrow night and I just picked up the trailer a few hours ago. I don't have running lights on the trailer. BRAKE AND TURN SIGNAL LIGHTS WORK as expected. Everything on the trailer worked as it should when connected to the trailer owners vehicle. This is my first time towing at night with the truck so I have never checked running lights before.
I'm using a 7 pin to 4 pin adapter and I've tried 3 different one, all without success. I continuity checked all the fuses and fusible links I could find related to towing and they all check out good. I continuity checked the pins in the 7 pin harness with the connectors for the 7 pin harness and that all checks out.
When I turn the park lights on one blue relay in the kick-panel clicks. I also tried swapping the 2 blue relays and didn't have any success getting the lights to work.
I printed the Trailer Electrical section from my 2005 FSM, but some of it doesn't match up to what I see in the truck so I'm not sure what I may have missed testing. Also note I've had the IPDM replaced at least once and I believe I've had the BCM replaced twice. That could be why the FSM doesn't match the equipment in my truck.
Here are pics of everywhere I've checked for fuses and what I've checked.
What the FSM shows for fuse locations:
The FSM says fuse one (bottom left) in the interior fuse panel is a trailer fuse, but on the fuse panel cover its labeled as Eng Cont Unit. I don't see anything there labeled Trailer or towing. I tested it anyway and it was good.
The FSM shows "Trailer Tow Relays" in a box between the battery and the first relay box, but I don't have that box in my truck.
Opening the first relay box I don't see any trailer related relays, but there are three blank spots they are labeled in the cover as "DTRL1, STOP LAMP, DTRL2". I assume these are supposed to be trailer/tow relays and they were initially supposed to go here, but now reside in the kick-panel.
Here is the IPDM and the layout of it looks nothing like the IPDM in my FSM. In the cover it shows the fusible link for trailer/tow. I tested it and it seemed good. I'm pretty sure I tested the other fusible link for the BCM and it tested good.
Here's the fuse layout of the IPDM. I checked F3 "DTRL RLY SUPPLY", F4 "TRAILER TOW", F7 "TAIL" (which I know is just the truck taillights), and F16 "TTOW REV LAMP".
I also checked two fuses under the steering wheel which I found out about here on CF. They checked out good, but from what I understand they should be for turn signals, not anything else.
The only thing I haven't done and don't really have the means to do is check the wiring from the relay harness to the back of the truck. Does anyone know if I missed checking anything else out?
Source: https://www.clubfrontier.org/threads/urgent-help-with-no-running-lights-on-trailer-that-i-need-tomorrow-night.105714/
Posted by: bibibibiprofferowe0266543.blogspot.com
