The Stovebolt Site Forums The Parking Lot '60-'66 Trucks Grounding issues 66 C10 rewire

PLEASE HELP!! I recently installed ez wiring 12 cuircuit hot rod harness in my 66 c10. I am having issues with grounding of the park lights and tail lights. When I activate the turn signals both of my tail lights are flashing. The housings are old and rusty which I'm guessing is the issue. I tried running a grounding wired from the back of the tail light housing to the back of the bumper where the tag bolts are cleaned both connections really well but now the tag light is blinking slightly with blinkers. My question is

What is the best way to ground these trucks to make everything work properly? I am trying to get around buying all new housings but I will if I have to. They are suppose to ground through the body when bolted in but this is not working for me. Any advice would be greatly appreciated.

Negative battery terminal is grounded to engine and body

I see that it doesn't say "frame" here. you need a good frame ground too

When you say ground you should apply overkill. Ground (s) might help. Cab to frame. Bed to frame. Hood to something to frame. And then add a few more. All that being said i have some new issues myself that i am curently troubleshooting so i am filing clean all housing and mating surfaces to make sure of ground.

This sounds more like a routing issue than grounding to me.

Dennis

Old, rusty bulb sockets are the pits to deal with. You might have to do some surgery on the tail light assemblies and adapt new, clean sockets to the housings, with dedicated ground wires running from the new sockets all the way from them to clean, tight connections on the frame. Ditto for the license plate light.
Jerry

I think I have to agree with DennisM, while you may have some grounding issues, this sounds more like a routing issue.
A couple of suggestions,
1)If you have the wires crossed at each tail light (I would assume the same for the park lights) you will end up with a weak tail light and a strong blinker. It has to do with the specific filament in the bulb used for either the blinker or tail/brake (or something along those lines). I know because I had this condition myself (it is easy to cross these if you are not using a stock harness).
2)Are you sure that you have the correct wires hooked up under the dash? You state that both tail lights are flashing. There is a separator coming out of the turn signals that send the flasher to the specific side yet still maintains the brake light being available at any time so you can check this connection and make sure you are correct. Even a non-stock harness should follow the turn signal/brake wire routing as shown in the shop manuals.
3)You state you are using a non-stock wiring harness (nothing wrong with that - i am doing it myself), so it may have come with a rear flasher capability (i don't recall that as an option on these trucks) and that may be the culprit if you are trying to have those function on your truck. Yes it can be done, but you have to have the wires routed correctly.
Finally, if you are concerned with a ground, pull the bulb out, run a specific wire (outside the truck) from the bulb directly to the negative battery post and put a trouble light in between, if you get a good light and you don't without the dedicated wire, yes you have a bad ground.