REAR BRAKE LIGHTS DO NOT COME ONLY TAP LIGHT IS

Wiring into the rear tail lights should be the right way to go. You should get access from inside the body or you may have to remove the rear light assembly to get to the wiring. You want to find the wire that goes into the socket for the rear break light. Be sure that you’re not tapping into a directional or amber lights. You should be able to figure this out visually or a cheap voltmeter might help you out.

Use a wire tap to avoid having to cut the wire. You can find these easily on eBay, which is where I found this picture By searching for a wire tap. You just Snap it on Both wires. Wrap it with electrical tape just to be sure it stays.

Are you sure the main brake lights are not coming on too? The work off the same switch. It sounds like your brake switch needs to be readjusted or replaced

I\'m assuming this is a regular pickup truck. You will need to tap into the harness at the rear of the truck. Inside the left rear frame rail, you\'ll find four wires. Brown=Tail, Yellow=L-turn/brake, Dark Green=R-turn/brake, Light Green=Backup. Your ground will be your chassis.

If you\'re looking to separate the brake lamps from the turn signals, you will need to go directly to the stop lamp switch and tap into the White wire. Once you have located the wiring, give yourself ample room and splice into each wire individually, one at a time. Use the heat shrink connectors. Do NOT use the blue scotch locks. Utilize split loom where possible to avoid chafes and rubbed through wiring that leads to short circuits.

You have a faulty earth connection on one of the rear lights ,or both ? try running a seperate ground or earth wire to each real light and iam sure this will cure the problem

Check the harness connection for trailer hitch lights near back bumper in chassis rail. launching a boat gets this connector corroded.

Check the trailer hitch tap connector in the frame near the rear bumper for corrosion. Use dielectric grease and reconnect the connector

did you mean the brake light in the rear of the car? if it is then the brake light switch is the problem. some time you can tap on the brake pedal and it will go out

Don't bother with a schematic...they all differ. Use a simple test light and just probe the rear light harness with everything turned off except for the brake lights, only one wire should show power. You can also check the color of the wire coming directly out of the bulb socket. I own a jeep, can read and draw wiring diagrams and have yet to find a diagram that has the same color coding as my vehicle.

if the hi mount brake lamp lights up then it is not the brake lamp switch, the other brake lamp wiring runs from the brake lamp switch through the turn signal switch. i would check all the light bulbs and sockets first because these cars like to burn out the grounds in the socket. i was a tech at a cadillac dealership for ten years, also had a 95 sts myself with the same problem. if that doesnt work then look toward the turnsignal switch and the wiring.

The problem is the turn signal/headlight/hazard switch assembly on the steering column which the brake light wiring runs through. The part is easy to change and cost about $50 at most parts stores