Brake Controller Wiring Installation in 1998 Chevrolet Blazer  

Question:

Expert Reply:

We do not yet happen to have shot an installation video for a brake controller in your particular year, make and model truck, a 1998 Chevy Blazer.

However, since you have already done the smart thing - testing with a circuit tester - you are just about there in terms of completing your installation. Vehicle makers often use the same color wire for specific functions but not always. Testing the wire with a circuit tester as you've done is the only foolproof way to find the correct connection points for a trailer brake controller.

The pigtail lead wiring harnesses supplied with most brake controllers, such as the excellent Tekonsha Prodigy P2 # 90885, have four wire colors and these connect to the vehicle as follows:

The WHITE ground wire connects directly to the battery negative terminal. The BLACK 12V power input wire for the controller connects through a circuit breaker (20-amp # 9506P or 30-amp # 38630, depending on the controller you are using) to the battery positive terminal. The RED brake signal input wire connects to the cold side of the brake light switch, the contact you identified through testing to have a signal only when the brake pedal is pressed. Finally the BLUE controller output signal wire for the trailer brakes connects through a length of 10-gauge wire (# 10-1-1) to the appropriate pin on your vehicle's trailer connector.

Sine I do not know what format trailer connector is on your vehicle you can refer to the linked article on trailer wiring to see which pin you should use for the brake controller signal. For example, on a 7-way the brake signal is usually carried on the pin at the 5-o-clock position as viewed from the rear of the vehicle.

expert reply by: Adam R

0