Tail Light Challenges

[seabeelt]

Should be a ground at each tail light. If the wires are different colors, that's ok as long as they go to the right places. Still sounds like you are missing a ground at one of the lights. Also the front side marker lights factor into the equation as the left rear side marker and right front side marker and front running light (inner bulb) are on the same wire (yellow) as the left rear tail light (third bulb in from the outside). Same goes for the other side, but reversed, connected to the yellow and white wire. If these are not connected and grounded individually, you will have problems. If you wired it differently than in my previous post it won't work correctly either. It also sounds like the mystery wire with voltage and lights on may be the trunk light wire. Trunk light is on all the time when the lights are on.

Doesn't it just drive you nuts when you cannot remember how you took it apart due to time and other things in life hampering our spider projects Thank goodness for this Forum and those who share their wisdom and knowledge
R/

[supplyguy]

The more I learn the more I don't know. From the last post, it makes sense - my right front parking light is out the same time as my rear left tail light. Why? I don't know, but for future use I now know there is a link. Called the mechanic today because I forgot to mention the stray hot wire in the trunk and he advised not to worry about it - all the lights are working (this gentleman is THE mechanic for DC Fiat members and a national treasure!). I may never know what the glitch was, or what this stray power wire is for (it is not for the trunk light, which is working just fine.). The good news is my car is safe to drive. Bad news is if it goes on the fritz again I will not know what went wrong.

[Franziskaner]

The mystery black wire, assuming its on the left side of the trunk is a ground wire. Try connecting that and see if it solves your problems. Sounds similar to an issue my son had with his tail lights. Ended up being that particular wire was loose.
R/

I know this an old thread but I ran into this issue today.. bad ground wires strike again !!! LOL

[SteinOnkel]

The mystery black wire, assuming its on the left side of the trunk is a ground wire. Try connecting that and see if it solves your problems. Sounds similar to an issue my son had with his tail lights. Ended up being that particular wire was loose.
R/

I know this an old thread but I ran into this issue today.. bad ground wires strike again !!! LOL

My entire taillight harness was so filthy that I built a new one from scratch and threw the old one in the bin. Not sure what happened, but everything was just caked with black crud. Really simple harness to build, took maybe 20 minutes. Food for thought.