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On the original 3rd brake light/high stop light I had 4 LEDs out. I replaced the brake light switch with the one from AutoZone and that didn't fix the problem. Put the original brake light switch back in and said screw it. That was a couple years back.
Just recently tried another brake light switch from AutoZone with the same result. Bought a new 3rd brake light assembly and installed it last night. All LEDs were lit up and working with the original brake light switch.
Today, I went out to test it again and the same 4 LEDs are out on the new 3rd brake light assembly. This is with both the original brake light switch and the new one from AutoZone. So, in less than 24 hours my new 3rd brake light assembly went from working perfectly to having the same 4 LEDs out as the old 3rd brake light.
What gives? All my wiring looks good. Is there another part I should be looking into? Searched the forum and can't find anybody with the same issue. Everybody else seems to have fixed their 3rd brake light issues with the switch only.
My guess is that the lights are being supplied to much voltage through a bad ground or through some other electrical issue. Easy fix would be to wire in a resistor in through the positive side to help dissipate some power.
New parts carry a warranty so you should be able to exchange it.
Edit, perhaps it might be a bad capacitor which is labeled "noise condenser" in the diagram
I'm not really sure where to begin with wiring in a resistor or replacing a possibly bad capacitor (or, where the capacitor is in the vehicle). Also, I wouldn't know what the values for each would need to be.
Also, the new 3rd brake light assembly was one somebody had laying around I scored off eBay. I wouldn't be able to return it if the electrical issue killed the 4 LEDs which absolutely sucks.
Thanks again.
ETA: I may have some .12 Ohms 1 watt resistors laying around from when I modified my turn signal relay to prevent hyperflash with my LED turn signal bulbs. Not sure if these would be what I need though?
Last edited by 95oRANGEcRUSH; 05-14-2016 at 01:49 AM.
1.) You can't get more voltage than what is originally there. So if there are voltage spikes taking out LEDs, you have charging system issues.
2.) If the resistor is bad, then the lamp assembly should be replaced/repaired. Adding in another resistor will likely just make it dimmer and/or work even more wonky.
3.) A bad capacitor "may" be able to cause you issues....but....in this layout, it is more than likely a very small capacitor to limit any noise being put back into the car when the lights come on and off. It "should" not cause any issues with the function of the lights. My "theory" is that this is more to keep from hearing static on your radio and such when the lights switch on/off.
My best guess is there is a bad connection somewhere providing power to the light. I have never taken this light out myself so no idea what to expect...but I would think that taking the light out and connecting to 12V power directly would be a valid test to see if the light assembly has issues or the rest of the wiring to the assembly has issues. You have already covered the basics which is to replace the switch which is usually the culprit.
Thanks for the feedback guys. I'll have to try and test it on a 12v source and see what I get.
Appears to be a power issue because I've changed the brake light switch twice AND the actual third brake light assembly twice. It's always the same LEDs that are out. Sometimes they light up and sometimes they don't and I've never heard of this on other TLs.
That's very odd... have you tried tracing the cable to the 3rd brake light to see if there's maybe a cut somewhere in the wire loom
This is basically what I was getting at by testing the lamp assembly when removed. I bet there is something wrong with the harness...or you just have bad luck.
05-06-2016, 07:10 PM
