Road Runner Nest

i'm nearly road ready with the chassis on my '71 GTX.

the taillights are acting really weird. Everything is LED bulbs except the main headlights.

1. car off, key out - taillights on, press brake, brakelights work like normal
2. lights on - brake lights come on, pressing brake doesn't change brightness
3. the only way to get the tails to turn off is to unplug the harness.
4. I checked both brake switches i have (old one in the car, and the new one i have. there is no difference)
5. turn signals don't work at all.
6. front lights all seem to work fine, except for an intermittent issue in the front parking light that i have figured out.

The headlamp switch is old. (that's the real suspect)

any ideas besides the headlamp switch?

sjd

First, check the grounding. The grounds on the tail lights aren't great, and a bad ground can cause all sorts of issues.

Second, what kind of LED's are installed? Some are just cheap garbage. Some are better than the original incandescents, just depends on what you actually have.

Third, turn signals. LED's have a very low amp draw, so you need a flasher intended for use with LED's. The stock flasher usually won't cut it, you need an electronic flasher.

Finally- did the everything work before you went to LED's? If not, maybe the headlight switch has something to do with it. If the tails worked before, it's probably not the switch, but the LED's or an issue with their installation.

electronic flasher...noted. I've never heard of a standard flasher not working, only thinking that bulbs were burned out.

i'll definitely check the grounds.

I have no idea if anything worked before, because the car was in pieces when i got it.

sjd

The old school flashers worked off of amp draw from the bulb, putting in a led bulb it will not work because there is a big difference in draw between incandescent and led. The led draws a fraction of what the incandescent bulb does. What incandescent bulb # did the led replace? It should be a 1157. Also make sure it's in correctly, If it's not it will do funky things.

It WAS the flasher. Just having it in the socket on the emergency flasher circuit was causing the tails to stay on. I pulled it, everything works as normal. I'm going to order a couple of LED flashers from summit.

sjd

You can get a heavy duty(trailer) or led flasher at any auto parts store.