Bizarre 3rd brake light failure.

[2112]

I happen to notice that my 3rd brake light was not coming on when I pressed the pedal.

I decided to bench test after removal using a car 12volt car battery. When contacting the terminals, it will sometimes illuminate, at which point making several other attempts will give illumination anywhere from 4 to 7 times.

Then nothing. No matter how many times or ways I contact the terminals, I cannot get it to function.

After letting it sit for a while, it will fire back up, 4 to 7 times then nothing again.

When it’s on, it is bright and all bulbs appear to be working fine.

What is going on? Are these LED? Is this how they fail?

BTW, these are not serviceable units as they come from the manufacturer.

 

[Art138]

I happen to notice that my 3rd brake light was not coming on when I pressed the pedal.

I decided to bench test after removal using a car 12volt car battery. When contacting the terminals, it will sometimes illuminate, at which point making several other attempts will give illumination anywhere from 4 to 7 times.

Then nothing. No matter how many times or ways I contact the terminals, I cannot get it to function.

After letting it sit for a while, it will fire back up, 4 to 7 times then nothing again.

When it’s on, it is bright and all bulbs appear to be working fine.

What is going on? Are these LED? Is this how they fail?

BTW, these are not serviceable units as they come from the manufacturer.

There are a few on eBay-one with best offer in case you can’t get yours to work.

 

[fjpikul]

Is this a totally stock car that only you have owned? A long time ago Black Ice invented a small electronic board that was easy to fabricate and install. It would make the third brake light pulse when you applied the brake pedal to make the car more noticeable when stopping. This was a very long time ago. I don't think anyone knows how many were made or installed. This is an outside long shot, just FYI

 

[2112]

Yes, stock. I have a pulsing unit I hoped to install, now I’m rethinking it.

 

[Submoose]

I’m no engineer but this sounds like the kind of response that is due to heat. There may be a broken connection that is so small it functions until resistance causes something to swell/move which breaks the connection. Now, that and the price you paid for my guessing is nearly useless but I’ve been confounded by broken connections many times and felt worth mentioning/

 

[2112]

maybe you are right and it's heat. It always seems to work when it's had time to cool,, just shocked that if it's heat, it builds up quickly and causes the unit to not illuminate

I will try getting the unit rebuilt before tossing it.

 

[PeteK]

Now that you have mentioned it, I better go out and check mine too.