98 tahoe brake controller wiring question

[strykerAKAmack]

Im hooking up a brake controller .
Ive got all the wiring done at the back end .Up front under the hood Ive found the Blue and orange wires .
Now....
The blue wire I need to get into the cab .
So is there a premade hole I can get thru Or do I need to get out the drill ?
The orange wire has a round terminal on the end of it So that gets hooked up somewhere in the engine bay ???
Inside The cab I guess I need to tap off the brake wire a ground wire and switched battery wire for going into the brake controller since It doesnt look like there is a plug for brake control wiring .
Weird how chevy gives the whole wiring at the rear of the truck then leaves you hanging at the front end for a quick ez job and makes you go jury rig it all together

Thanks

[DmaxMaverick]

You can "piggy back" along another harness passing through the firewall, inside an existing grommet. I use a wire clothes hanger (straightened out) and push it through along side another harness. Once through, make a small hook on the end, insert the wire, then crimp the hook closed. Pull it back through, being very careful to not damage the existing harness, or the grommet. It's also a good time to pull through a couple other wires for future use (12 and/or 14 ga, and perhaps a 1/8" tubing for a boost gage). Once through to length, tape/tie/conduit the wire on both sides of the firewall to clean it up.

[arveetek]

Open up the black fuse/relay box under the hood on the driver's side fender toward the firewall. There are two fused studs pointing up at the rear of the box. Attach the orange wire to one stud, and this will supply power to the "charge" line at the rear of the truck, to charge the battery on the trailer you are towing.

You can use the other stud to supply power to your brake controller. You'll have to supply your own wire and ring terminal for this.

Yes, you'll have to tap into the brake light switch under the dash. It will be a small, white wire bundled together with a bunch of other wires.

I agree, it's odd the way GM made their wiring choices. By 1998, both Ford and Dodge had easy to use "plug and play" wire harnesses that made installing a brake controller a real breeze. GM didn't do this until 2001, and then changed the wiring schematics in 2003, and then ditched the plug under the dash altogether in 2007. Now all late model trucks only have 4 wires dangling underneath the steering column, with no plug. At least the wiring is all there, however. Still, it's much simpler to purchase a brake control with a pre-made harness that plugs right into your truck.

I remember the days where every brake control installation meant hours of running wires from front to rear, installing fuse blocks or circuit breakers, and tapping into brake light switches. I loved it when the mfg's started making the pre-wired trucks with "plug and play" harnesses...turned the brake controller installation into a 15 minute job. Now, a lot of the trucks are coming with brake controllers installed from the factory! I don't sell as many brake controllers as I used to!

Casey

[JohnC]

I remember the days where every brake control installation meant hours of running wires from front to rear, installing fuse blocks or circuit breakers, and tapping into brake light switches.
To say nothing of tapping into the hydraulic brake lines and bleeding the brake controller...

[arveetek]

To say nothing of tapping into the hydraulic brake lines and bleeding the brake controller...

Oh yeah! I had forgotten about those as well. When I first got into the business around '95, hydraulic controllers were becoming a thing of the past.

You would think that I would remember, though, seeing as how I had one on my '81 all those years! :rolleyes:

Casey