1997 does NOT plug in like the rest.
Follow my instructions and you'll be fine...
Pop the hood and pull the cover off of the fuse box on the driver's side fender. There should be two silver, threaded, posts at the back (firewall) side of the box. Just in front of those posts should be two 30 amp maxi fuses. Pull those fuses and set them aside. You don't want to risk frying anything while you hook stuff up.
Under the brake booster will be a bunch of wires taped/wrapped up in split loom. Look for a bundle that seems to just keep folding over on itself. You may see a heavy gauge dark blue wire, and a heavy gauge orange wire wrapped up in the tape. Pull those two wires loose. Watch your knuckles because they may just "let go" while you are in the middle of a good pull. The tape is going to peel away from the wires and your hands will be a sticky mess, so you might think about a glove, or have some hand cleaner handy to wash off with before you go messin around under the dash of your truck.
The orange wire will have a square ring already attached to it. That wire can just slip over one of the posts on the fuse block. Use one of the 8mm nuts to tighten it down. You will have to drill a hole through the firewall, or find a rubber grommet, to push the blue wire through. I usually just drill a 3/8" hole through the firewall, just to the driver's side of the brake booster. You will see a small circle with a tiny divet between the backside of the under dash fuse box, and the brake booster. Go right through that little divet and you won't hit anything. You might think you have when you hit the back side of the carpet, but unless there is any kind of aftermarket box behind there, you will be fine.
The orange wire you hooked to the post on the fuse box is the battery charge wire. That is a 12v+ source to charge travel trailer batteries, batteries you might use for a trailer mounted winch, interior lights on an enclosed car hauler or utility trailer, etc... That wire will always be hot once you plug those maxi fuses back in. The blue wire you fed through the firewall is the brake wire. That is the wire you will hook to the output wire on the brake controller.
Now you need to use a peice of 12 guage wire to run power from the empty post on the fuse box, through the hole you made in the firewall, and hook it up to the brake controller that you are going to mount under the dash somewhere. I usually mount my controllers down low, and to the right. Just about in the middle of your right shin as you are driving. I drill up into the bottom of the dash, so that if the truck is ever sold or traded, and the controller is removed for use in the next truck, the holes won't stick out like a sore thumb.
Now you have your brake wire and your power wire under the dash. Now you have to find the brake light switch wire that will trigger the controller.
Your 97 Chevy is special. It is the only year Chevy truck that uses this wire, so anyone else using these instructions will be lost when they look under the dash. As a matter of fact, I have come across 97 Chevy trucks that weren't even like this, so if any of this seems like it's not right, stop and PM me and I will help you find it the best I can. First things first, don't mess with any wires that are held together with yellow clips or yellow tape. Those wires are for the airbag, and messin with those could set it off. You can move them around, but don't disconnect any of them, and don't probe any of them looking for the brake light wire.
*the wire you want*
The convenience center at the firewall just under the emergency brake pedal... Remove 6-8" of tape covering the main loom of 40+ wires. You will find a smaller bundle of wires.
You will find:
5 WHITE wires
4 lights guage wires (16 guage)
1 heavy guage wire (14 guage)
Multiple wires wrapped in yellow tape... the ones you don't want to mess with.
Probe the 4 light guage wires with a test light. The wire that is cold until the brake pedal is pushed, and does not flash with the hazard lights is the correct wire. Splice into that wire with a wire tap, then wrap up the rest of the wires.
Take your last wire to the negative side of the battery, or to a good chassis ground, and you are done wiring the controller.
At the back of the truck, on the driver's side frame rail, you will find the other ends of the blue and orange wire taped up against the wire loom. Wire those wires to the appropriate terminals on the plug in the back, and you are damned close to being done.
Straighten up your wires and make everything looks really clean. When you are done you probably won't see where any wires were added or hooked up unless you really look for them. When you are happy with the way things look, pop the fuses back in the the slots that they came out of in the under hood fuse box.
