"Solved" Hot wire

[tomloans]

I need a good heavy fuse positive wire at the hitch. Going to run a relay off the reverse lights and install bright back up lights. Dont want to drag a hot wire from the front to the back to do it. Will the door lock button at the hatch do it?

This is for a 1999 GMC Yukon. Thanks much for any info.

 

[BG1988]

I need a good heavy fuse positive wire at the hitch. Going to run a relay off the reverse lights and install bright back up lights. Dont want to drag a hot wire from the front to the back to do it. Will the door lock button at the hatch do it?

This is for a 1999 GMC Yukon. Thanks much for any info.

Run a new wire (have it fused close to the battery as possible.) never try and tap power from other locations... most likely will fry something if you try it..

 

[bigdog9191999]

Run a new wire (have it fused close to the battery as possible.) never try and tap power from other locations... most likely will fry something if you try it..

have to agree with this, unless your running some led type that are lower power draw and basically eliminate the oem lights so the overall power draw is close to stock so your not overloading the system. otherwise a separate power wire is the way to go, but by all means tap the stock lights to trigger the relay to turn them on .

 

[TJ Baker]

I need a good heavy fuse positive wire at the hitch. Going to run a relay off the reverse lights and install bright back up lights. Dont want to drag a hot wire from the front to the back to do it. Will the door lock button at the hatch do it?

This is for a 1999 GMC Yukon. Thanks much for any info.

Fairly often there is a large 12 volt auxiliary wire running to a 7 pin trailering connector. Have you looked into this possiblity?

 

[tomloans]

Thank you for the all the answers and I agree. Regarding the 7 pin connector. I took all the tow wires in the back and one by one tested them to see if there is a live wire when the car is running and there is nothing. I am working on my 1999 GMC Yukon. I also have a 2003 Tahoe and this vehicle has the 7 pin and all you have to do is add a fuse in the box and the hot wire lights up in at the connector in the back.

 

[tomloans]

TJ Baker, what color would this auxiliary wire be?

 

[Eman85]

Many times GM left the 2 wires unconnected at the front near the brake booster. I can't swear if a 99 is the same but on my 98 and 97 the wires for the trailer brakes and the auxilary power were looped and taped near the booster. There are studs at the fuse/relay box on the left fenderwell to tap fused 12v that can handle the amperage.

 

[tomloans]

Many times GM left the 2 wires unconnected at the front near the brake booster. I can't swear if a 99 is the same but on my 98 and 97 the wires for the trailer brakes and the auxilary power were looped and taped near the booster. There are studs at the fuse/relay box on the left fenderwell to tap fused 12v that can handle the amperage.

OK I will take a look. Thank you that is inline with info I found on the web but more clear!

 

[exp500]

Even if factory wire is not there, this vintage pretty easy to add the wire. Good luck and report your progress.

 

[BG1988]

Thank you for the all the answers and I agree. Regarding the 7 pin connector. I took all the tow wires in the back and one by one tested them to see if there is a live wire when the car is running and there is nothing. I am working on my 1999 GMC Yukon. I also have a 2003 Tahoe and this vehicle has the 7 pin and all you have to do is add a fuse in the box and the hot wire lights up in at the connector in the back.

under the hood it's disconnected at the factory

 

[tomloans]

I will let you know. I have done this before installing a power switch under the steering wheel so I can turn on the severe LED lights without going into reverse. No sweat. Thanks for the input! I will be back as soon as I figure it out!

T

 

[tomloans]

OK I found an orange and a blue wire tucked away behind the brake booster. I checked the two terminals behind the fuse box and noticed they are always on. Great now where in the world do the two wires orange and blue terminate? Here are pictures...

Under the hood and wiring in the back. Where is the blue and orange wire in the back.

 

[Fless]

Blue is typically the hot line to the brake controller, probably goes to the underdash wiring if you have it, then on to the trailer wiring. You have only 6 conductors in that connector and are probably missing the brake wire, or the auxiliary power wire at the connector. Those would be two heavier wires.

 

[tomloans]

Thank you. Here is a good video to glean data from...

Best wishes and thanks for the responses.

 

[tomloans]

Here is a video made on this subject. Hope it helps someone....

 

[Fless]

Good info. I don't know why one wouldn't use the standard 7-blade trailer connector, though.

 

[tomloans]

I know what you mean. I installed this 7 blade connector like the connector on my 2003 Tahoe. I can plug in a seven blade trailer or if the flat 4 or 5 wire connector, I carry one of these in the truck as well...

https://www.amazon.com/WOFTD-Traile...at+adapter&qid=1621282327&s=automotive&sr=1-3

 

[Fless]

I replaced my whole 7-blade with a Hopkins combo - 7 blade and 4 flat. #40920. Snaps right in to the OE 7-blade connector hole, no screws, and to the OE harness. My towing is either with 7-blade or 4 flat.

https://hopkinstowingsolutions.com/products/vehicle-wiring-kits/vehicle-specific/40920.html

Ignore the rust, I've since sanded and painted everything...

 

[tomloans]

Yes that is perfect.

 

[bigdog9191999]

I replaced my whole 7-blade with a Hopkins combo - 7 blade and 4 flat. #40920. Snaps right in to the OE 7-blade connector hole, no screws, and to the OE harness. My towing is either with 7-blade or 4 flat.

https://hopkinstowingsolutions.com/products/vehicle-wiring-kits/vehicle-specific/40920.html

Ignore the rust, I've since sanded and painted everything...

View attachment 279474

that little surface rust. lol


but yes it is odd, most have a 7 blade stock. i believe i was having issues somewhere in the connection of mine and i was always having issues, i finally got fed up and cut it off and installed an aftermarket 7 blade. now i just need a hole saw to put it where i want it.