'08 GM 2500 trailer wiring / safety issue?

[AirsDream]

Bought an '08 GM 2500 for towing, with HD tow package, integrated brake controller, including "Heavy-Duty Trailer Wiring Harness Package" etc. All set to pick up my Airstream on Saturday. Well, not quite ...

Reading the owner's manual, came across this, buried on p. 4-91: "The fuses for the [trailer brake and battery feed] circuits are installed in the underhood electrical center but the wires are not connected. They should be connected by your dealer or a qualified service center."

In other words, plug in the trailer fine, but the brakes won't work! (nor will the coach batteries charge.) Called the selling dealer. Was told that this was not done as part of delivery prep, and that they in fact don't and won't do it: "We don't do that - it's a liability issue." WTF??!!! liability issue indeed! - how about no trailer brakes and the unsuspecting driver? THAT sounds like a liability issue to me. Went to a second dealer. They were willing to TRY to help, but the service mgr. cannot find a procedure on their GM computer for locating the wires, connecting the wires, etc.

Does anybody here know where these mysterious wires are or how to connect them? I'd be happy to do this myself if I could figure it out ... it seems pretty clear that the General is not going to be of help!

Thanks.

Ryanh

[DEITZ645]

AirsDream,
I have an '06 GMC 2500 with the HD trailer package and all I had to do was install a 40 or 50 amp fuse in the underhood fuse box. On mine there was a "dummy" fuse in the spot with a sticker over it. Then I hooked up the brake controller with a cable provided with the Tekonsha Prodigy I purchased. All I had to do was remove a cover on a box on the cab side oft he firewall and plug it in. That was all I had to do. Don't know why they would have made it more difficult to hook up an '08.

I think all you will have to do is put a fuse in the underhood fuse box and the extra wiring is for a 5th wheel set up as decribed below...

There was an extra wiring harness that came with mine for use in wiring a 5th wheel trailer, but that is not needed. That one gets plugged into a jack that is attached to one of the frame rails on the dirver side somewhere under the bed of the truck.

Hope this information helps.

[AirsDream]

Thanks for the info, but this situation is different; the brake controller came built-in, and the fuse(s) are there ... no dummies, real fuses. But the wires are not connected and are hidden somewhere. I have no idea where or why they are hidden ...

[DEITZ645]

Ryanh,
Are you sure the extra wiring isn't for the 5th wheel set up? You could always take a multi-meter and meter all the pins on the 7-pin plug on th hitch. I think the positions are labeled on the dust cover of the plug recepticle. Start the truck and put the ground pin of the multimeter on the ground pin of the plug and the positive pin of the multimeter to the brake pin on the plug and then have somebody step on the brake. If you get current then you are set.

I guess you could also use a test light to accomplish the same thing.

[Bambi_Bandit]

DEITZ645's info wont help if you have a 2008. From 2007, GM Full Size trucks there is no longer an electric trailer brake controller pigtail harness.

Since you have the intergrated controller, you are looking for the "AUXILIARY POWER" feed. Look at steps 8-8.4

Chevrolet Questions & Auto Repair Information > connect tlr brake controller 2007 silver > Chevrolet Questions

Hope this helps...

[Foiled Again]

Thank you Bambi Bandit. Your link showed exactly what I had to do with mine.

Paula

[DEITZ645]

Geeez, I guess I should be glad I got an '06. Hooking up the trailer breaks was a breeze for me. One plug, one fuse, and done.

[AirsDream]

Thanks, B-Bandit ... I just came back from my garage, where I did in fact locate the auxiliary power feed wire(s) in question, but NOT the brake wire .... and another issue is that my machine has JL-1 (Integrated Brake Controller), so these instructions don't apply ... as the answer man said, "The information for a truck with (JL1) will be in my next post. There is a difference in the wiring. Thanks"
So now all I've got to do is to find the "next post" which ought to get me to where I'm going. Terrific lead. Thanks very much. If I can't find the "next post" I may write back to you for more help!

[safari 28]

Now this really sounds like a typical GM stunt. Why are they so small minded in thinking this would some how save a penny, and not realize how they just pissed off a customer who just spent 45k plus. Pitiful!

[Bambi_Bandit]

Originally Posted by AirsDream

Thanks, B-Bandit ... I just came back from my garage, where I did in fact locate the auxiliary power feed wire(s) in question, but NOT the brake wire .... and another issue is that my machine has JL-1 (Integrated Brake Controller), so these instructions don't apply ... as the answer man said, "The information for a truck with (JL1) will be in my next post. There is a difference in the wiring. Thanks"
So now all I've got to do is to find the "next post" which ought to get me to where I'm going. Terrific lead. Thanks very much. If I can't find the "next post" I may write back to you for more help!

This thread / forum may be of better help to you with quicker answers and ideas:

Trailer/5th wheel wiring on 2008 LMM? - Diesel Place