Man...I spent about three hours today on my back, with my head jammed under the dash, looking for this elusive bundle of wires above the parking brake assembly...I'll be damned if I can find it! There are several wire bundles, but nothing loose or obvious...everything there is already connected to something. It's makin' me crazy...

1997 LT Blazer with factory heavy-duty towing option. (8 wire bundle in the back, which is nicely wrapped and secured with a tie wrap.)

Any help is appreciated. I've been scouring the net for the past few days, and can't find anything that directly relates to my vehicle.

 

The information provided in this thread is applicable to the 98+ s-series trucks. I cannot locate any information that states that the 96-97 trucks were pre-wired for electronic trailer brakes.

How many wires do you have at the back of the truck?

 

I've heard somewhere that someone found theirs under the center console? don't hold me to that though.

 

8 wires at the back of the truck. The red and dark blue wires are heavy gauge. It's definitely wired for trailer brakes, I just don't know where the other end is.

 

If you have 8 wires at the back, then there should be provisions for a brake controller.

Maybe look near the center of the dash as suggested.

 

I looked up my VIN, and found these two RPO codes

UY7 TRAILER WIRING,7 WIRE,2 LEAD FRONT HARNESS,5 LEAD REAR HARNESS 7 WIRE TRLR HARN

and

Z82 TRAILERING PACKAGE(SPECIAL)(REESE TYPE HITCH) PROVISION FOR HD TRAILER EQUIP(Z82)


So if anybody doesn't feel like getting on the ground, then look in your glove box for those 2 RPO codes. I'm guessing this means I have the HD tow package. lol

 

uy7 '2 lead front harness' elaborate...

 

Again, 98+ vs. 96-97. cbr has an 01. The UY7 RPO code description varies depending on where you look, but it stands for the HD trailer wiring package. The '2 wire front' consists of the terminals at the underhood fuse box for +12V to the trailer aux. circuit and +12V to the trailer brake wiring under the dash.

 

Alright then...I couldn't find this wire bundle under the dash, because on a 1997 Blazer it's not under the dash!! It's in the engine compartment, below and to the left (as you face the front of the car) of the junction block, taped to another wire loom. Here's some shots of the blue wire, red wire and inline fuse...partially unwrapped in the first picture, and with the tape cut away in the second. Looks like I've got some wires to run through the firewall, and I'll have to figure out where to tap into the brake switch.

 

There ya go. Glad you found them!

Once the blue wire is routed under the dash, all you need is a good ignition power source, ground, and the tap off the brake switch.

As far as the brake switch goes, tap off of the white wire which is the switched output to the multifunction switch and the CHMSL (center high mount stop lamp).