Under the dash, behind the park brake pedal is a fuse/relay
panel, just like on the tow package trucks. The brake controller
will plug into the top row of plugs, second over from the left.
Plug the brake contoller harness into that socket (I sell the
harness you need)
Now, under the hood, is the main fuse box. You are gonna have to take the cover all the way off this one. On the chevy trucks I have done, you mist remove the corner fender brace from the fire wall to the fender. Two 13mm bolts on the firewall, and two on the fender.
With the brace out of the way, you can take the main cover off the fuse panel (remove the top cover, and the main cover) The cover just snaps on, just pull the lower sides out, and it will come off.
Once the cover is removed, you will see two studs, on the engine
side of the fuse panel, that were covered up with the cover. Also,
you should see a red wire with a eyelet on the end to slip over
the stud. Put this on one of the studs (it is supposed to be the
8mm to the front of the truck) If you need a nut, it is 8 mm
coarse metric thread. (the other stud is 10 mm Coarse metric
thread).
Now you will see the row of large fuses. At each end of this row,
the last fuse powers the stud next to it. Put a 30 amp fuse in the
empty slot next to the stud you used if it does not already have a
fuse in it. This should supply power to your brake controller.
Next, locate the thicker dark blue wire taped back, it the area of the underhood fuse box. Normally it is just folded back, and taped to the wire harness, and may have a un-used plug on it. This is the brake wire FROM the brake contoller. If you see it, and it is not hooked to anything, your truck does not have the tow package, sorry. You will need to connect to this Dark blue wire to the trailer plug at the back of the truck.
I also connect a wire from the red one you connected to the stud in the fuse panel, and run it back to the trailer plug too. This gives you the 12 volt supply many trailers need to run insude lights, or charge break away batteries on the trailer. I use two conducter, double jacketed 12 OR 14 Gauge wire. One wire connects to the blue wire you just located, and the other one connects to the same stud you connected that red wire to.
(in the picture above, I show you the red and blue wires, and the
grey 2 conductor wire I have run to the plug at the back of the
truck. I am in the process of hooking up. I have already hooked
the red wire to the new black wire, and will be connecting the
blue wire to the white wire. The blue wire WILL be connected to
the white wire, I just cut the factory plug off)
(Close up of the blue wire and plug. Plug is not used, the blue
wire will be connected to the white wire, and ran to the rear of
the truck. In the picture, I have already hooked the red wire to
the black one.)
Run this wire all the way to the back of the truck. Strap or tie it up out of the way, so it will not get cut or chafe on metal an short out. I usally zip strap it to the main wire harness that runs along the frame.
At the back of the truck, the blue wire (or the wire you hooked
to the blue wire up front) connects to the "blue" terminal on the
plug, and the red wire connects to the "black" terminal on a
standard 7 way plug. The trailer lights are already at the
back of the truck, use your owners manual for wire colors. I THINK
they will be Yellow is left stop, Green is right stop, Brown is
parking lights, light blue is the high mount stop light. (check
you manual to be sure!) Plug terminals are labeled as follows:
Red, left turn/stop. Brown- right turn/stop, Green- running
lights. Dont hook up the high mount brake light.
Here is apicture of a Late 90 early 2000's truck that did not have the tow package but chevy DI include the wires, they just did not hook them up! Look under your hood for these wires!:
One quick note, I am working on a few pictures of the early
1998 and older trucks, that have NO plug. I have found that
on many of the older truck, they do have a "panel" on the firewall
under the dash, sort of behind the park brake. Normally grey
plactic. I have located on A FEW of the trucks, a brake light
source. It was the two pin hole marked "TAN" ALong the bottom if I
remember, and it was the right pin. Check it with you test
light, should light up when you hit the brakes. Otheriwise,
getting to the Brake light switch is a hassle!
