Brake Controller Install on 1995 Chevy C Series Pickup Truck

Question:

Have 1995 C1500 Chevy PU. Want to add brake controller. Saw video regarding 93 but still have questions. I have two large blue and red wires that run form hood to spare tire not being used assume came with Z82 trailer/tow package. The kit in the video shows without these wires. Also, can not find connection location for under dash wiring end from controller. I have a picture of j-box that I do have if you want to see it send direct e-mail address. What do I need to complete the install of the ETBC7 and 90885 Prodigy?

asked by: Tom M

Expert Reply:

The Blue and Orange (or Red) wires are meant to carry the 12-v accessory power and the brake control output to the 7-way installed at the rear. The wires terminate in the engine compartment under the master cylinder. The red wire would be lengthened and connected to the positive battery terminal via a 40 amp breaker included with the # ETBC7 kit and the blue wire would be extended through the firewall and connect to the blue output wire of the brake controller. The black brake controller wire would connect to the positive battery terminal via a 20 amp or a 30 amp circuit breaker, also included in the kit. The instructions provided with your brake controller should indicate which is needed.

The red wire from the brake controller connects to the cold side of the stop light switch. However, bracing under the dash makes directly accessing the stoplight switch very difficult. There is a junction box near the emergency brake pedal. Look for a terminal on the junction box that is labeled 'NAT' (there might be more than one). Use a circuit tester like part # PTW2993 on each of these terminals. If one of them shows voltage when the brake pedal is pressed, you can get the brake signal there. You can a female push on terminal like # DW05709-1 to make the connection.

If you can't find a signal there, you can access the third brake lamp circuit, which you can find in the wiring harness under the driver's side threshold. Once again, use a circuit tester on the wires in the harness, looking for a wire that goes hot only when the brake is pressed.

The # ETBC7 would provide the adapter to convert an existing 4-pole into a 7-way. If you don't already have a 4-pole, you can easily install one using part # 118315. The adapter plugs directly into the 4-pole, with four wires remaining. The blue wire would connect to the blue wire you found on the frame member. The black adapter wire connects to the red wire you found. The white wire grounds to the truck frame, and the purple wire which usually carries the reverse light circuit. If needed, it can be tapped into the reverse light circuit, otherwise it can just be taped off and bundled up out of the way.

I'll link you to the instructions for the # ETBC7 kit.