Volkswagen Owners Club Forum banner

rear light ground

996 Views 6 Replies 4 Participants Last post by  dock_root
I don't even want to describe my wiring situation but if somebody could tell me where all the rear lights are supposed to be grounded to I would appreciate it. My caddy 's was wired to be pulled behind an rv and not well.
1 - 7 of 7 Posts
It has been a while since I fooled with the rear lights but I seem to remember that the brown wire was screwed to the body of the truck behind the lights themselves. If not just run a wire and do it.
My rear left running light is grounding through the right one I believe aananand there is a brown ground wire on on the sides. however, none of the left lights seem to be connected to the ground on the same (left)side. As told by measuring no continuity on my multimeter. I thought the writing diagram showed all the rear lights grounding at the same location but ultimately the wiring back there is such a mess I was hoping to find were the original ground wires were connecting. Failing that I may ground each bulb on it's on but would be interested in hearing people's ideas as to best ground location back there. I read somewhere about running a ground back to the front?
Well the bane of the VW's are grounds, you have to have a good Battery to Frame, then Frame to engine ground, and if you haven't replaced the main two grounds it wouldn't do anything but help you to replace them now.

The rear lights were always cascaded from left to right or right to left on the Rabbits and Cabriolets that I have owned. When I have had a flaky issue on my Diesel Rabbit, or my Cabriolets, the first thing that I have done was to separate the grounds left from right, and I have made new grounds on the left to the frame and the right to the frame as it is less resistance of the ground and less flakiness to deal with.

As mentioned I would separate the grounds and tie them to each side respectively as long as you have a good Battery to Frame ground.
If you have good frame points and a good frame connection on the front, then clean and buff an area, Drill a small pilot hole or use a bolt that is grounded but be sure to clean the bolt shiny, as well as the point of contact, and it wouldn't hurt to add a small modicum of Dielectric Grease to the bolt, Never-Seize works as well.

Yes you could run a new wire, but there isn't a need, but alas on the Caddy, the bed had rubber mounts, and they did run a bonding wire from the bolts to the frame IIRC to make sure that the bed was grounded to the frame and it could be that your bonding wires are corroded to the point where they aren't of any use.
So be sure that you ground the Bed to the Frame which is what I would do.
See less See more
on my truck there is a separate ground for the left and right rear lights behind the covers--the left one gave me the most trouble-unscrewed it, sprayed with solvent and it's ok----the Bentley manual locates all of the grounds for every component
I have already done improves battery to transmission mount then mount to frame ground up front. Rear lights are grounded separately on each side. I even tried grounding the one light separately and it still doesn't work even though it is getting 12v and has it's own ground? Must be doing something odd through the stop light circuit? Everything has been shoddily wired to be pulled behind an rv so there are wires hanging that i dont even know what they are. I'm not sure about this bed to frame ground though I should check on that. I don't think there is one that I can tell but where would it be located? Also thinking about running a ground back to the front. Probably should just rewire the whole thing I've always had gremlins with blinkers/stop lights. Ugh...
1 - 7 of 7 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.