I have a 96 f350 Crewcab with a 7.5l I recently swapped the bed out for a flatbed. I hooked the lights up to the flatbed as i would with any other truck and while they all work if I have the key on the taillights are on but they are very dim.... I checked for voltage and I am actually getting voltage (4.079 V DC) on the turn/stop wire for both sides. this only happens when the key is on and the running lights are off of course. Has anyone ran into this problem?

 

i have a 95 f350 4x4 dually that does the same thing. havent found the cause but canadian vehicles have a daytime headlights system so i figured it may have something to do with that.

 

Hey Fdude check out this thread I found in the electrical section sounds like it is the cause of my issue and could be the fix for yours too. https://www.ford-trucks.com/forums/1...-the-time.html

 

very interesting