I have a 1994.5 f350 with the 7.3 powerstroke, I've had this truck for 4 years and the taillights have started giving me some grief the last 2 summers. They don't work in any weather above freezing. Anything like 36 degrees or below and they work fine. Trying to figure out what could cause it. Fuses are fine. I'm not an electrician but the only thing I kind of have is very dim turn signals on both sides. Any help is greatly appreciated. Thanks.

 

We always look to see if there is anything that both the tail and signal lamps share and that is their ground connection.

To confirm that is easy , just run a clean piece of wire from a good ground to any one of the taillight ground connection sometimes you just need to touch the outside of the tail lamp bulb base. Try that and see if there is any difference.s