New Brake Light failure mode discovered--fix not discovered
07-31-2009, 10:46 AM
#1
Three Wheelin'
Thread Starter
New Brake Light failure mode discovered--fix not discovered
Did a search on the brake light failure modes and have not been able to find anything quite like what I have going on.
Here is the situation:
1) Running lights work just fine (I take that to mean that each socket on the tail light harness is getting power)
2) Third brake light works when brake pedal is depressed (I am guessing this means that the pedal switch and the bulb control units are working)
3) Neither one of the tail lamp brake lights works--could this be a bulb? The genius kid at AutoZone sold me a single filament bulb that when installed lights up like a brake light, all the time.
4) The stop lamp warning light is coming on as it should.
Anyone have any ideas? Am going to get the correct (recommended by Alan) 1157 bulbs in the hope that will fix things...
Here is the situation:
1) Running lights work just fine (I take that to mean that each socket on the tail light harness is getting power)
2) Third brake light works when brake pedal is depressed (I am guessing this means that the pedal switch and the bulb control units are working)
3) Neither one of the tail lamp brake lights works--could this be a bulb? The genius kid at AutoZone sold me a single filament bulb that when installed lights up like a brake light, all the time.
4) The stop lamp warning light is coming on as it should.
Anyone have any ideas? Am going to get the correct (recommended by Alan) 1157 bulbs in the hope that will fix things...
07-31-2009, 11:06 AM
#2
928 Collector
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Each brake light bulb/socket has two filaments and two circuits and two electrodes. So simoly-put, looks like your brake light bulbs have the brake part burnt out, OR the socket electrodes or accompanying circuits are toast. Check the socket when the brake is depressed with a volt meter.
07-31-2009, 12:21 PM
#4
Racer
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I just did this exact same thing last night...working on tail lights. The previous owner, in his infante wisdom installed a new socket from some other vehicle. Then proceeded to wire it up backwards. Then instead of fixing it, just installed the dual filament bulb backwards! HAHA So after about 30 mins of testing all the wires, found the right ones and hooked it up nicely.
A volt meter is your friend, esp in a porsche.
A volt meter is your friend, esp in a porsche.
07-31-2009, 07:06 PM
#5
Electron Wrangler
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Well given the center brake light works sounds like the circuit to the back is probably OK. Yes get the 1157's and try that - could certainly be the brake filaments burned out - however both at the same time is odd.... you should have go at wanrning for whichever went first...
Save the new bulb you got - you can use it in the center brake light (assuming its an 1156).
To your 1) No - it proves only the the markers are fine and that each socket's ground is OK - nothing more...
Alan
Save the new bulb you got - you can use it in the center brake light (assuming its an 1156).
To your 1) No - it proves only the the markers are fine and that each socket's ground is OK - nothing more...
Alan
