1999 GMC/Chevy trailer wiring

[Robyn]

Well I had to try and figure out the wiring on the kid's 99 GMC 4x4
The truck has the factory trailer package with the wiring to the back of the truck.
All the stuff works and the kids bought the compatible trailer brake controler and it works fine too.
There was no 12V power to the back to power the trailers interior lights.

There is a red wire in the plug harness that goes to the proper prong in the plug but no power.
This is a red wire. Where does the power get picked up??
Does this originate in the aparatus/junction box under the hood on the LH side.

The kid needed power to the lights for tomorrow eavening so I disconnected the red wire and tied a jumper to the tailight feed so when the park lights are on there is power to the interior light switches.

Any hints as to the red wires point of Origin would be helpful.
I hate to tear into stuff to find it.

Thanks

Robyn

[DmaxMaverick]

The fuse/source is in the underhood junction/fuse box. If the power lead has never been used, there may have never been a fuse installed, or it has blown and never replaced.

[Robyn]

I will have to have a peek.
It was raining today and the most important thing was getting the interior lights hooked up and working.

A did look in the fuse panel but not real well. Its not raining now so I will have a look see before it gets dark.

The Son Inlaw can reconnect the red wire and remove the jumper from the tail light circuit when he gets time.

Thanks

Robyn

[Robyn]

Well I had a look in the panel and found the fuse for the #1 stud (aux) to be missing.

A further investigation of this is in Order when the weather is more hospitable.

Nice touch having a fuse for the trailer lights too instead of running all the lights through one fuse.

Best

Robyn

[DmaxMaverick]

I don't remember exactly on the '99 (been a while), but the #1 sounds right. Yep. It's nice to have isolated trailer fuses.

[rhsub]

Robyn
On my sub the red wire was tied to the harness under the brake booster, I hooked it to one stud and used the other to power my electric brake, they used seperate maxi-fuses for each stud
Good luck hope it quits raining soon
Ron