Weird Tail Light Problem

[mello mike]

Discovered this problem tonight after repairing my right tail light (this problem effects both sides, so I know my repair didn't have anything to do with this newly discovered problem).

Both turn signals and brake lights work just fine without the running lights in the on position. However, when the running lights are on and you apply the brakes or one of the turn signals, you can see a very faint difference in brightness for both lights. To me it seems like the tails lights are at their full brightness when the running lights are on, thus the very slight difference when the brakes or turn signals are applied. Wierd problem, eh?

[DPeakMD]

Bad ground somewhere!

[mello mike]

Originally Posted by DPeakMD

Bad ground somewhere!

Hmmmm! Thanks, Dallas. Can a bad ground on a running light cause this problem? I messed up the ground on one of my Peterson LED running lights tonight.

[DPeakMD]

It would just for that light. I think if it's something where it changes based on the brake/turn light being on or off, the problem is with the brake/turn light ground since that is the common point.

[ROBERTSUNRUS]

Hi, a bad ground would cause either a feed back or dim lights. Since you stated that the tail lights are at full brightness, I would say that you have both lights wired backwards. In other words, you have your tail lights wired to the brightest filiment of the bulbs and your brake and turn lights wired to the dimmer filiment.

[mello mike]

Originally Posted by ROBERTSUNRUS

Hi, a bad ground would cause either a feed back or dim lights. Since you stated that the tail lights are at full brightness, I would say that you have both lights wired backwards. In other words, you have your tail lights wired to the brightest filiment of the bulbs and your brake and turn lights wired to the dimmer filiment.

Interesting. That is possible. The wires for my new socket were both black. I'll reverse those as see what happens. Thanks...

[Maryw164]

Mike,

We'll be adding the new LED tail/backup lights too. Hopefully your issue my help us avert any problem for us. That is if it was a grounded or backward wiring issue.

Thanks, your new "friend",

Mary

p.s. I left you a profile comment & sent you a PM too. Check them out.

[Aerowood]

Originally Posted by Maryw164

Mike,

We'll be adding the new LED tail/backup lights too. Hopefully your issue my help us avert any problem for us. That is if it was a grounded or backward wiring issue.

Thanks, your new "friend",

Mary

p.s. I left you a profile comment & sent you a PM too. Check them out.

I installed LED's on my 71 GT. You should not encounter any wiring problems with them as the posts are clearly marked. Do buy the 90 degree or right angle pigtail as there is not enough room for the straight style.

[mello mike]

Originally Posted by ROBERTSUNRUS

Hi, a bad ground would cause either a feed back or dim lights. Since you stated that the tail lights are at full brightness, I would say that you have both lights wired backwards. In other words, you have your tail lights wired to the brightest filiment of the bulbs and your brake and turn lights wired to the dimmer filiment.

Well ROBERTSUNRUS was right!! The wires were wired backwards. The weird thing is that the previous owner who "fixed" the left tail light years ago wired it backwards, too!!! Anyhow, the right tail light works great and looks great (just got my new lenses).