'06 Duramax 7 pin connector ?
 

OK,

where does the red wire in the 7 pin get it's power from? Should be 12v, I got nothing. Is it fused? This is what is killing my electric hydraulic brakes from working. I have variable voltage output at the trailer signal pin but need the +12vdc pin live to turn on the pump for the hyraulics on the trailer. If it makes a diference I have dual batteries. Normally I always have the shop manuals for my vehicles but of course this one I don't have. Need to drag this bad boy tomorrow, any help would be appreciated, thanks

It "should" all come through the factory harness; it "should" also be fused. Check the underhood fuse box, diagram under the lid should point it out. There should be spares in there and also in the box on driver's side of dash.

There is an empty fuse location in the fuse box under the hood. It should have a "dummy" fuse in it from the factory. It will be a red plastic plug that actually looks like a fuse. Pull this out and replace with a Green 40 amp fuse. If you purchased the truck new it should be in the glove box or console along with you harness for your brake controller. Will probably be taped to this harness and won't be easily seen.

Plug it in and problem solved.

Buck

what buck said.

I dont know why they do it that way, but they do.

Buck,
Thanks,

That was it. Still have the wrong controller but the brakes worked great for the 35 mile haul today. All goes well, we'll be splashing Saturday.

Glad to hear it worked out for ya.

Buck