Brake Controller Install on 1997 Chevrolet Pickup  

Question:

Expert Reply:

This is a fairly straightforward install. GM has already run some of the necessary wiring from the rear frame rail area to the engine compartment, so you will see a blue wire for the electric brake function, and an orange wire which provides 12 volt power for trailer accessories like a breakaway kit near the end of the driver side frame rail. The orange and blue wires at the rear of the truck would attach to the appropriate poles on the 7-way trailer connector on the rear bumper. You can see wiring schematics in the wiring FAQ I've linked for you.

I would recommend the Prodigy P2 brake controller # 90885 for your 1997 Chevy Silverado, because it is easy to use and it includes a pigtail that you will use to hard wire the unit. Take a look at the instructions at the link provided.

We offer a 7-way, part # ETBC7, Brake Controller Install Kit which includes the trailer connector and all necessary installation hardware for the brake controller. If your truck does not already have a 4-way connector, you will first need to install a T-1 Vehicle Wiring Harness, part # 118315. I am including links to the instructions for the 4-Way, as well as a typical installation video featuring the # ETBC7 kit.

The orange and blue wires terminate in the engine compartment, and they can be found under the master cylinder. Follow the brake lines down to where they start to turn back under the cab. The wires will be bundled up, and are usually wrapped in electrical tape. The orange wire would be extended and ran to the positive battery terminal via the 40 amp circuit breaker included in the install kit. The blue electric brake output wire would be extended and ran through the firewall to attach to the blue wire on the brake controller. Make sure that the opening you use in the firewall has a grommet or that you wrap the wire with a layer of electrical, to prevent the metal from cutting the wire and shorting out.

The connections for the brake controller wires are not too difficult either. The blue wire from the brake controller would as mentioned be attached to the wire that was run through the firewall. The black wire, the power wire for the brake controller, will be run through the firewall and attach to the positive battery terminal, using either the 20 or 30 amp circuit breaker included in the install kit. Use the 20amp circuit breaker for trailers with 2 to 4 brakes, or the 30amp breaker for trailers with 6 to 8 brakes. The white brake controller wire is a ground, and will be run through the firewall and attached to the negative battery terminal. The red stop light wire, which seems like your main concern, would attach to the brake stoplight switch.

In your particular model year truck, the stoplight switch is extremely hard to access, so I typically recommend accessing the circuit through the main wiring harness located under the steering column. The necessary wire is either light blue or white in color and when probed with a circuit tester such as part # PTW2993, will only show voltage when the brake pedal is applied. Tap your red brake controller wire into that circuit.

Another possible access point is the junction block located un the dash near the emergency brake pedal. The block will have a couple of male blade terminals labeled 'NAT'. Use a circuit tester on both terminals. If one of the terminals goes hot only when the brake pedal is pressed, you can install a female blade terminal on the end of the red wire and access the stop lamp switch signal there.

You can view some additional information on wiring your vehicle for a brake controller at the links provided.

expert reply by: Mike L

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Terry W.

3/22/2024

I have a 1997 Chevy pick up truck. I was reading your article about hooking up the brake line. You suggested hooking it up to the accessory box below the emergency brake pedal labeled NAT. Unfortunately on my truck they did not provide a wire going to that particular NAT. I believe the wire is still behind that unit. Do you know if the wire is light blue or white. Also there is a light blue wire going to the emergency brake could that be used?

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Mike L.

4/8/2024

@TerryW We don't know whether it's the light blue or the white. You can use a circuit tester like # PTW2993 to see which wire goes hot with the brake pedal pressed. Or, you can access this signal at the 3rd brake lamp on the back of the cab. Hope that helps!

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