Where to start on a turn signal issue

[krumpelsaurusrex]

My passenger rear turn signal does not work. I replaced the bulb, and still no go. When the turn signal is on, you can see a very small (1/8") part of the light element flashing. But its not enough to see with the lens on. My first though is that the flasher in the dash is bad. The other thought is that the PO did install wiring for a trailer to be put on the hitch. So maybe bad connection? I'll probably get to looking at it friday or saturday. Where do you think I should start?

[kaptnkaos]

if it is getting some power, then check the ground.
Poor grounds are the most common problem with the lights on these trucks.
Find where the ground is.. remove the screw, clean the area real good, as well a the connector, then apply a little dab od di-electric grease to the point of contact and the wire end, put the screw back in.
Next to duct tape, di-electric grease is the second most important tool we outta crarry in our tool box.

KaptnKA S

[fordman]

yes the grounds shoul dbe checked first. then there are two famous places to look for crossed wires. under the bed near the rear and under the dash coming out of the column. someone may have tried to hook up trailer lights in the rear and got them wrong or they are coming apart. or someone may have done soem column replacement or a turn signal swithc replacemnet that went wrong. if all the wires look good. then the third place to look would be the turn signal switch and the contacts inside of it.

[krumpelsaurusrex]

In general, where would the ground be?

[towtruckerfour]

I have 2 70's. When you pull the tail light assembly out, there is a ground behind it. I would check that one first.

[krumpelsaurusrex]

I am almost sure its a ground issue. with the signal on, when i pull the light housing out and away from the truck, it stops working, but when it makes contact with metal it seems to work. Both sides do this. The passenger still is never as bright as the driver side. The wiring under is horrible. I'll have to spend some time undoing the trailer harness the po installed. Why do people try to do stuff they just can't do. And then attempt it, but just do such a crappy job? I mean there is all sorts of exposed wire from where the connections were made. Hmmm, bare wires under a truck.. rain and water... not to bright of an idea.

Thanks for the start, now I know where I need to focus to solve this issue

[cep62]

I saw where somone smushed all the wires under the crossmember doing a clutch swap.
That caused some issues.