I've got an issue where with a 2004 Gen 2 where, the R brake light first didn't come on at all, then after wiggling some wires, it comes on dimly. The L is fine. I took the carpet and rear right side panels apart, but the only thing visible seemed wiring to the lower incandescent bulbs. So I'm wondering if it's the Right rear unit, or if it's the wiring since it's dim, but not completely out? Any tips on debugging this? Since the lower incandescent bulbs are bright, I'm sure I'd measure 12V there, but I don't see where the voltage to the upper LEDs for the brake lights goes, in order to measure? I did not remove the unit, just examined from the back inside the car side. Thanks for any tips.
Gen2 Prius left and right LED brake lights that stop working is a pretty common problem. Easiest is to replace entire taillight with aftermarket replacement. They are not that expensive on Ebay. If you have lots of time, you can try and take apart the lamp assembly and repair the LEDs and/or driver circuitry.
Thanks, I see a bunch in the ~ $80 range, but one thing on my 2004 is it has wiring to 3 incandescent bulbs, but I don't see where the wiring goes to the LEDs? If I measure 12V on any of the incandescents, does that mean my wiring is good, and a replacement will be fine? Since these are not Toyota parts, but compatibles, are some better than others? I'd hate to have to do this multiple times. Now on the car side, there is a white plug inserted that looks like it could be pulled out, but the left one is fully functional, and I don't see anywhere on the R one that could use any plugging in anywhere other than the 3 incandescent twistys? Is this going out a sign of the 12V battery going down? I did the measurement test (cycling buttons, and battery seemed OK).
The aftermarket lamp assemblies on Ebay are all pretty good quality and come with their own integrated lamp harness/bulb sockets. Since the OEMs have problems with LEDs, I'd rather use new aftermarket than used OEM. The lamp assemblies have one white connector that connects to the car wiring harness. Simple plug and play installation. (sometimes you need to transfer over the incandescent bulbs but they all come with new LEDs)
My drivers side rear tail light LED brake lights were out. I got an OEM replacement (used) and replaced it and the replaced tail light did not go on. I then plugged the replacement into the passenger light connector (same input and output connector) and the replacement worked. (My old light had only 1 of the LED's out.) I could not find a good wiring diagram for checking the connector pins (I am a total novice at auto electrical) but I did use a jewelers (very small) flathead screwdriver on the connector to try to tighten each pin connector and it actually worked. We'll see if it holds for more than a week.
