Patrick - LED Taillight problems

[Xack]

Originally Posted by DanEC

The car is down for winter maintenance items right now but it runs 14.5V at idle. ERA runs grounds from each tailight frames to a big bolt for the bumper brackets and I install serrated washers at all grounds. All are tight and I have multiple grounds installed from the drivetrain to the frame. Everything functions properly and is bright (for filiment bulbs). If I had ground problems I think it would show up in the blinker and brake light circuit also, which worked fine with the LED bulbs.

I mean the LED bulbs are working fine in my GTX with a 47 year old wiring harness, taillights and Mopars known reputation for electrical issues. A large number of these things burned up by the mid-70s due to electrical problems. If it was simply a bad ground or resistance issue that was the problem I can't explain how they could possibly function in my old Plymouth.

I appreciate the pointers. When I get the car out again and it warms up I may get out my meters and do some more checks on the tailight circuit. But I kind of wore myself out earlier, trying to fix something that wasn't obviously broken. I'm curious to see how Large Arbor does with them.

Ok. But you've only proved the bulbs work by putting them in another car. That's good, but your problem still exists on your Cobra. The bulbs are good. The circuit works as long as your battery charger provides higher voltage than is available by just your battery alone. New washers don't mean you've fixed a bad ground.
Good luck!