wtf is going on w my brake lights
 

I have an 02 SC430. I put the 06 tail lights in probably back in 2008. I just recently noticed, so I am not sure if this is a new problem or was like this since installation, that when I press the brakes a little the brake lights light up but if I press the brake pedal all the way down the brake lights are no longer lit up. Why would this be? How can I correct this?

check your brake fluid level

Checked the brake fluid, it's fine. Seems like, according to my mechanic friend, that it's the brake light switch....

It should be an easy thing to check.

Crawl under the driver's side dash and press one hand down on the brake pedal...enough to release the pressure from the switch (the switch that activates the brake lights is installed just above the pedal - it's depressed when you're NOT pressing on the pedal and releases when you press on the pedal).

When you have the pressure off the switch, you can reach your other hand and wiggle/press/release the switch.

Have someone stand behind the car and see what the brake lights do. If it seems intermittent (i.e. if you wiggle the switch and the lights flicker) the switch is bad.

I'd also try pressing the switch in (so that the brake lights go off) and slowly releasing it...the brake lights should just come on at one point during the switch travel..and stay on. If they come on, then go off, then come on, etc...while you're releasing the switch, it's bad.


EDIT: DO NOT DO THIS WHILE THE CAR IS RUNNING OR IN ANYTHING OTHER THAN PARK!!!!!!!!!

This should go without saying but, so does "Don't stick a metal screwdriver in the cigarette lighter plug"...and..well... :)

Yea, we did this and it's definitely bad. I ordered a new one and with shipping it was just $26 from RockAuto.com....

this started to happen to me, not sure if the switch is bad, im going to go check

update, it was the brake fluid

interesting about the brake fluid...so would it be safe to postulate that the brake fluid was not at a sufficient level, thus causing relative loss in brake pedal pressure/travel to contact the switch properly?

The fluid level sensor in the master cylinder reservoir is a contact sensor, so it is either on or off. If the fluid is at just the right point it will trigger on momentarily while the vehicle is in motion going over bumps and corners as the fluid moves around in there .

SC's are relatively sensitive on the brake fluid level...for good reason too. My RX-7's were very sensitive too. As Bob mentioned even going over bumps and hills would cause the light to go on and off as the fluid fluctuated in the reservoir. Glad it was nothing big...another common but annoying problem solved with a quick DIY and good sense!

I dont think brake fluid level has anything to do with brake lights not working properly. It can only be the brake pedal sensor.

no its definatey the brake fluid sensor, I asked the dealer and they confirmed. It was going off only over bumps in the parking garage and sometimes at sharp turns, things like that. I filled to just under the "max" line. It took a little less than half of a small bottle of fluid.

Im not talking about the "brake" light on the dash the op was talking about his rear brakelights, brake fluid level will not effect your exterior brake lights

oh lol yea your right!

I wonder if the OP ever resolved his/her problem and found out what the root cause was....?