The orange "lights" warning light on the dash came on and all of my brake lights even the 3rd brake light in the window suddenly stopped working. Tail lights and all others work. What would be the likely cause of this? Brake pedal switch gone bad? How can I test it? I don't see a brake lights fuse under the hood... is it under the dash?
The likely cause of the problem is a corroded or loose ground somewhere. A wiring diagram would help trace the ground locations so you can check, but start in the trunk.
The brake pedal switch is easy to test. Unplug the connector and check for continuity with a multimeter or continuity tester when depressing the plunger on the switch.
There is nowhither fuse box under the dash on the driver's side.
I will try to get a wiring diagram. There was a ground wire coming loose on the driver side brake light and I fixed it (again). That problem started a few years ago due to a loose ground screw at the bulb connector, which melted the plastic around the screw. In the past it didn't cause all brake lights to stop working, just the one bad side. All of the trunk and 3rd brake light wiring looks good now and I believe this is a new problem since it affects all brake lights. I searched the group for answers and I think it might be the switch, relay, or some electrical control box. The 20 amp stop light fuse under the driver dash looks good. I found the pedal switch and it is way up near the top of the dash and very difficult to access... I was able to unplug the connector but I'm not sure if I can test with a multimeter without removing the switch. Each time I press the pedal I hear a solid click coming from inside the center console, near the auto transmission shifter. I think it's the control that unlocks the shifter when the brake pedal is pressed. Since it activates does this indicate that the pedal switch is working? How can I test the brake relay? I don't know where it is located. I see some fuses and relays under the passenger side dash near the heat/AC fan. Engine is 4 cyl with cruise control if it helps.
I still think you have a bad or loose ground somewhere. First check if you have 12 volts coming into the brake light assemblies. If there is, then a bad ground is the culprit and you don't have to mess with fuses, relays, etc.
If you don't have 12 volts, then check the fuse with a meter - not visually.
The 20 amp stop light fuse
The brake light switch is probably working if the shift lock interlock is working.
How can I test the brake
I'm not sure that there is a brake light relay, but to check any relay, check if the power switches on and off with relay activation.
I didn't get a voltage reading at either brake light assembly connector except 0.1 at one lead on each side (driver and passenger). The fuse is good and I inserted a new spare just to make sure. I didn't find any other loose grounds.
A few older posts mentioned a yellow "lamp failure sensor" box in the trunk near the top of the driver's side wall. I removed and opened it up and the circuit board looks good (no burned marks). Puzzled, I did a little more searching and found more info in this thread:
By the way one of the best features of 87-91 generation Camrys is the 4 big tail/brake lights stretched across the entire trunk except the license plate. Newer models have fewer or smaller lights so they are harder to see and might be more prone to rear collisions. I especially dislike the narrow 97-01 generation lights, which look like they are falling asleep. The current generation is better.
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