Hey all, I just bought a 2008 Dakota a month ago and I'm lovin it! A nice upgrade from my 99 Blazer. I looked through the forum but couldn't find any info so I thought I'd ask and see if anyone can provide some help. I'm going camping in a few days and will be towing my 12' aluminum boat for the first time with my new truck. I just checked the 4 pin plug at the back and am only getting running light power, the turn signals/brake lights have no power on the 4 pin or the 7 pin. Is there a particular spot I should check or should I tap into the turn signal wires at the rear lights on the truck? Let me know, thanks.

 

I see you are in BC. Do you have a Princess Auto near you? They have 4-wire and 7-wire testers that will help you figure out if it is the truck or the trailer. If that is not how you are testing it already.

Also, if your 7-wire is working you can get a converter.

My experience is that ground is almost always the problem! After that, it is a short somewhere on the trailer.

We had an auxiliary set of lights on our scout trailer (for when the canoe rack is on, and someone strapped the canoe right over the wiring - shorted everything out and blew fuses on a couple of the mini-vans before they called me.

There is a thread here about wiring for the trailer connector - use the search feature to try to find it.

 

Check the furse panel under the hood. May have a blown fuse on the trailer brake lights.

 

There was a TSB on the 2008 that might be part of your problem.

2008 Dodge Dakota Electrical System Service Bulletin 243532


NHTSA: Action Number: 10026066 Service Bulletin Number: 243532

• Report Date:
  Jul 01, 2008
• Component:
  Electrical System

Summary: Chrysler: reconfigure front control module. The 4-way electrical connector for trailer lights on about 20,600 of the above vehicles may not function properly due to an improperly configured front control module (fcm). Csc was received.

 

Thanks for the responses guys.

I was actually at Princess Auto yesterday and picked up the 4pin tester for $2 and that is how I found out there was a problem then I used my multimeter to test the 7pin plug and found no signal power on either plug.

I did find that TSB but it didn't make much sense to me. So I thought I would look at something more simple.

Then I looked at the service manual wiring diagrams that I found here online and I seen that the trailer signals have seperate fuses and relays than the truck. So today at work I checked the fuses. They were ok. Then I pulled out the relays. I gave them a shake and I could here them both rattle. Weird. I put the horn relay in to test both signals. That worked. So I pulled the relays apart and found an identical failure in both. The contactor inside was broken off. Here's a pic of them both. I lost the small piece from the first but you can see that the crack is identical on both.
IMAG0186.jpg

I stopped by the parts store after work and will have new relays tomorrow. I'm not a fan of the price though. I seen them online for $5.99 but my cost at the parts store was $21 each. The guy is gonna give em to me for $18 each though. The part number at the store is RY4231. The numbers on top of the relay itself are 56049018AB and 72472V made by TYCO (which I thought was a toy company) and on the side of the relay by the diagram is 2507 and MEX 0736602A.

Hopefully this info will be useful for the next guy.

 

Take it into the dealer and have them fix it. My 2008 did the same thing. The computer in the truck was not programmed to use the 4 pin harness. A quick computer update at the dealer and it worked great. Just bring the TSB number with you to be sure they know what you are talking about.