Questions and Answers

Mitsubishi Diamante Brake Lights Don't Work
Q. Hello, My name is Gillian and I own a 1993 Mitsubishi Diamante. My question is this; I have checked and replaced the bulbs, fuses and relays for my brake lights and I cannot find out why they don't work. I have narrowed it down to the brake switch under the brake pedal but I don't know exactly what to look for. Can you help?

My turn signals work and all the contacts are getting power but the brake lights including the interior brake light don't work.

Thank you for any advice and assistance...

A. It could be a bad brake light switch. They are easy enough to check with a test light. The brake light switch is located on top of the brake pedal. It's held in place with a double nut that also allows for a certain amount of adjustment.

To check the brake light switch, probe the orange/green wire with a test light. There should be power there. If there is, push down the brake pedal and check for power at the green wire. If there is no power there with the brake pedal depressed, the brake light switch is bad. If there is no power at the orange/green wire you have a break between the switch and fuse 17. Uhh... you did check the fuses first, right? If not, check it before you crawl under your dash board.

If you have power on both sides of the switch, then you have a break in the wiring between the switch and the brake lights. To check this, access the rear combination connectors and check for power at the green wires there. If you don't have power you have confirmed a break in the wiring between the brake light switch and the brake lights.

If you do have power the next thing to check is the ground side of the brake lights. The ground is located inside the trunk, under the rear shelf. You can run a wire from the black wire at the rear combination connectors to ground and if the lights come on, you have a bad ground side.