Another NEW brake light issue...

[Square_78]

I searched and didnt find this probem.

Everything worked fine except my left tail light had a loose connection and the tail light would go out. Banging on the side of the bed would make it flicker and come back on. brake lights and signals worked fine. I figured a loose or bad ground.

Today I pulled the tail light assembly out, everything looks good, cleaned the bulb socket. NOW i have both tail lights and both brake lights, BUT when i turn on the headlights and the tail lights are on, I dont have brake light on left side. If i turn off the headlights, then the left brake light works.

What the heck is going on? Ive obviously done something while i was in there trying to fix it. It worked before. Im assuming i may have pulled off a ground wire? The harness on the back of the tail light was pretty tight. Can I just run a new ground wire from the back of the tail light down to the frame?

This is just the strangest problem ive ever seen

Lonnie

[Square_78]

Does the tail light bucket itself need to be screwed into the bed as a ground also? I was testing everything with the bucket hanging by the wires. Maybe after I screw it back in, it will work? I cant get back out to my shop untill tomorrow to work on it again.

[truckster]

The ground to the tail lights is through the body's sheet metal. You shouldn't need to go to the frame, as long as the body is grounded. The contact between the tail light housing needs to be good, though. That is where the ground is established for the bulb.

[Square_78]

I'll try screwing the housing back into the body and see if it works.

[Andy4639]

Clean the inside of the brake housing where the 2 screw go through. Make sure they are making good metal to metal contact.

[c10monkey]

Had that problem with my front turn signals on my 71. Ground is your problem. Make sure the housing has good contact with the sheet metal... Now if you notice, the bulb socket is crimped into the housing. That crimp is the ground. Corrosion developed between the crimp and housing. If you twist the socket back and forth, you will make a better connection. But will happen again. I'm thinking of putting a small screw through the socket flange to see if that is more permanent.

[Square_78]

Haha you guys were right! I never tried it with the housing screwed into the body! I'm an idiot! What a waste of time. It works fine now
Thanks everyone. Hopefully this thread will help someone else with the same problem in the future.

Lonnie
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[cdowns]

over the years i've got in the habit of running a ground wire from one of the crossills on the box to the framerail or crossmember to assure good grounding of the box

[Square_78]

I'm used to working on new vehicles where everything is plastic. I'm not used to having to ground out light housings and such. I'll know for next time tho. I might run myself a good ground wire from the frame to the bed anyways.
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[Sicklajoie]

I had the same problem and came across this thread.
Cleaned up a little corrosion where the housing meets the sheetmetal and all is well now. Thanks for the advice!