I have power through my Prodigy and throughout the output connector to the 6 way Z82 Jumper. I have full trailer lights but no electric brake power at the rear of the truck trailer connector - dark blue wire. Fuses check ok. It is not the Prodigy, harness or trailer. 100% sure on that. It has to be the between the electical center where the 6 way connector plugs in and the rear of the truck. Any ideas?

There is a connector under the underhood drivers side fuse panel cover. You need to remove the 4 10mm bolts on the fender braket then the cover pops off. You are looking for a blue wire with a plug on it plugged into an other blue wire. If they are not plugged together then you need to do so.

Oh, also quite often people wire the brakes of a trailer to the center pin of the plug. This is not correct. GM follows code so you need to put the brake control wire to the terminal marked blue. The brake wire should also be blue.

There is a connector under the underhood drivers side fuse panel cover. You need to remove the 4 10mm bolts on the fender braket then the cover pops off. You are looking for a blue wire with a plug on it plugged into an other blue wire. If they are not plugged together then you need to do so.

Thanks, I will check that. I ran a temp jumper wire form the dk blue wire underneath the dash to the rear of the rear connector dk blue wire and the brakes worked. So something isn't connected somewhere.

I had a similar problem with mine too. :eek:

I installed my Prodigy Tuesday, hooked it to the trailer and thought all was OK. I used the manual lever to test braking power and it read fine so I thought I was good to go.

Yesterday, when I drove the truck, I noticed that touching the brake pedal didn't "wake" the Prodigy from it's sleep mode, figured I must have hooked up the wrong wire to the brake feed circuit.

Pulled it all apart and I found I had the correct wires spliced, so then I tested for 12 volts on the light blue wire in the factory harness with brake pedal depressed, still no juice. I pulled the connector out of it's socket and tested at the pin where it feeds from on the connector block, still no juice. :rolleyes:

So, figuring the General must have wired this baby wrong, I snipped the light blue wire and ran a jumper up to the the cold side of the brake light switch on the pedal.

Works fine now. :grd:

What the hell is this about having to go under the hood and connect a wire, nothing in the owner's manual about that? :confused:

I found a dark blue wire disconnected. Now I need to find someone to press the pedal while I run a test light back there. I will report back shortly.

BTW on the 06 I found that you have to remove the black plastic cover that is held in place with 4 tabs around the fuse box. I had to remove the brace that has 4 bolts with a 13 mm wrench to be able to lift the black cover out.

Connected and tested and now it has power throughout. Now I need to test it on the trailer. My trailer is in getting something fixed so I won't be able to do that until next week but I am fairly certain this was the problem.

Thanks Max Power!!!

So it was disconnected under there? Strange, but at least it is an easy fix. I bet the dealer wouldn't have figured it out so easily ;)

Yep, disconnected. I almost took it to the dealer. They had my truck 8 days before they could even look at it when I had a bad convertor. I think you saved me from going through that again!!!!

I had the same problem with a Voyager. Call Tekonsha for the correct wiring scheme, I do not remember which wires, but two wires are called out in the manual that have to be switched. When I hooked mine up, it was dark so the auto lights were on and the brakes worked fine, however, something with the new ('03 and up) auto lights that has to be wired differently from the scheme in the Tekonsha manual. I found this out in the mountains of Tennessee pulling a 30' tt when I realized I had no trailer brakes. Stopped and bought a new controller, same thing. Later I called Tekonsha and they knew exactly what the problem was. I switched two wires and wa-la problem solved.

GM changed their wiring in 2003.... Tekonsha has a bulletin on their web site describing the change...

What is strange to me is that is sounds like both the gents above have a wire unplugged under the underhood fuse panel.... Has GM changed their mfg process to leave this unplugged?

What is strange to me is that is sounds like both the gents above have a wire unplugged under the underhood fuse panel....

Yep, I figured the light blue wire with the brake switch signal circuit was unplugged somewhere but it was quicker to just run a jumper and solder it in place than to trace down to where it might be disconnected. :exactly:

The dealer would probably have have it several days to trace it down. :rolleyes:

It could also be the fuse on the CMHSL being blown that gives you the brake input signal.

It could also be the fuse on the CMHSL being blown that gives you the brake input signal.

Yep, it was! Checked the third brake light this morning and sure enough, it wasn't working. :confused: Thanks for the suggestion, I didn't realize that light was fused separately from the other brake lights.

It could also be the fuse on the CMHSL being blown that gives you the brake input signal.

Am filing this away for future reference, but what is the CMHSL? Thanks

CHMSL - Center High Mount Stop Lamp.