tail light and front signal problem

[lead foot caveman]

I'm having a weird problem with my back driver side and front passenger signal lights...m front signal comes on and off randomly ..if I hit the fender with my fist it will come on and go back off..I take it that its a nad ground maybe? My tail lights work but when I press the brake the driver side goes out..I put new bulbs in all around and it didn't cure my problem...any ideas?

[70_F100]

Sounds like bad grounds on both ends.

[basketcase0302]

My 71' has ground wires from the front light assemblies that are screwed onto the radiator support if memory serves me correctly. I'd also look at the ground strap on the front frame horn to radiator support, (it's by the DS bumper bolt hole) and make sure the rear tail light assembly is grounded good. Might want to look at the contacts on the light socket themselves real close also.

[lead foot caveman]

Thanks guys..any idea whete the tail lights are grounded

[basketcase0302]

lead foot caveman on Sat Dec 31, 2011 10:39 pm
Thanks guys..any idea where the tail lights are grounded

Please excuse me, few years since I've owned a Ford truck with a factory bed on it (flatbed owner).
It has to be somewhere here on the below diagram, maybe someone else can chime in here to help?

[70_F100]

IIRC, there isn't a separate ground wire for the taillights. They just ground through the mounting screws.

[basketcase0302]

Thanks Richard! So the housing would need to be grounded good when screwed into the bed?

[70_F100]

Thanks Richard! So the housing would need to be grounded good when screwed into the bed?

Pretty sure that's right.

There are two screws that hold the housing to the bed, welded nuts on the back side of the hole. If everything is good and clean (pretty tough on a 40+ year-old truck ) the ground shouldn't be a problem. Might have to scuff up the housing and such with some Scotchbrite or something to get that good ground, though...