My brake lamp warning on the dash went off(the one below engine maintenance required). I thought I remembered being told the brake light was actually out. So before bringing it to the safety inspection, I bought a replacement lamp and went to the trunk to change out the bulb. I opened up the panel on the left rear and fumbled with the wiring for a second before it occurred to me that I should make sure it was the left side. So I checked by pressing the brakes. The lights(all three) worked. I had my wife verify while lights were both on and off and the brake pressed. No problems. I brought it to the safety inspection. They said it could be the brake reservoir issue, but checked and found no problem. So they passed me. I returned the bulbs to the store. They told me it could be the bushing. I checked and it wasn’t. I notice specifically that on starting the van the light doesn’t appear right away. I press the brake all the way in and then it comes on and stays. Anyone know why? I don’t mind it, but I am about to sell the van and the aesthetics matter. Thanks in advance!
Are you sure the brake fluid level isn’t slightly low? Honda had a recall on certain master cylinders that were leaking:
It’s important you get this checked out by a mechanic. If the brake light comes on, it means there may be something wrong with your brakes. Very dangerous. This isn’t something the inspection station is likely to be qualified to diagnose. Actually, I’m surprised they allowed the car to pass. When a car won’t go, that’s one thing. But when you got 2 tons of metal going down the road and it suddenly won’t stop, that’s another thing entirely.
So what’s causing it? Could be something wrong with the brake hydraulics. Or with the emergency brake. Sometimes the alternator warning light and the brake light circuitry is shared, so it might be something wrong with the alternator. Does the alternator warning light come on when you turn the key to “on” before you start the engine?
Edit: Neither of my cars shows a brake warning light when one of the brake light bulbs in the rear is out.
I don’t think the brake warning light comes on in any vehicle to show a bulb is out. None that I’ve seen anyway. The problem is more than likely a low brake master cylinder or the emergency brake is not adjusted properly just as @GeorgeSanJose mentioned in his comment.
Actually, I just got ahold of the manual and it explains my problem exactly. “If a brake light does not work, the BRAKE LAMP indicator comes on when you push the brake pedal with the ignition switch ON”. So it looks like it is mistakenly thinking the bulb is out when it is not…time to fiddle with connections…
My car has a brake lamp out indicator that is separate from the brake system warning light. I had a similar problem with my car that turned out to be corrosion in the socket. If the resistance got too high, the light would still work, but it would set off the indicator. Cleaning out the socket and using dielectric bulb grease has worked so far.
Check to see if one of the license plate bulbs are burnt out.
Some of these Rear Lamp Out warning systems will turn on if one of the license plate bulbs burn out.
Tester
Thanks for the advice! Will do!
Sometimes there are two lamps in the third cyclops brake light. If one of the lamps is out, the lack of current flow is enough to trip the monitor module. You might not even notice the second bulb being out on cursory viewing.