Neither of my rear side marker lamps work because they are not grounded. I don't see how they ever worked because the housing itself does not seem to be grounded. The bolt end and metal housing I am pointing to in this picture is grounded. Is there supposed to be a jumper between that bolt end and the one right next to it that is part of the side marker lamp housing?
ground for rear side marker lamps
- Thread starter Jeff
- Start date
There are two wires going into the lamp socket, one of them is the ground. You need to look at the wiring diagram for the rear harness to see where the ground is connected to the body or frame. That connection is either corroded or disconnected.
Dave
Dave
65sporty
Old Man with a Hat
If adding a jumper wire fixes it, do it. I have seen some side markers that will ground right to the inside of the quarter panel. 68 GTX has a round one and the large nut holding in to the quarter has serrations to dig into the metal providing ground. Looking at your pic it looks like it's a single wire, so ground has to come from some where.
65sporty
Old Man with a Hat
All that matters to me is if it works, how often will people look in your trunk anyways.
The little plastic sockets have a metal insert that grounds to your bracket which then grounds to the body via contact. My 68 has zero ground wires to the tail lights. It relies on the socket contact to a metal part that is expected to ground through the body. New paint in the wrong area or corrosion will limit the ground.
My car (1970 Fury) also has no ground wires for lights at rear of car. My backup lights dont work because of lack of ground. Fixing those will be harder. It seems the bumper has to come off for access.
The pot metal housing for these marker lights mounts on a larger plastic piece so I dont know how they worked originally.
The pot metal housing for these marker lights mounts on a larger plastic piece so I dont know how they worked originally.
If memory serves me correctly, the whole marker assembly is grounded to the fender by the large C shaped bracket that holds the marker assembly to the fender. One corner of the plastic marker housing should have a metal tab that goes over one of the studs holding the bracket and the pot metal piece and there should be a metal tab inside the socket that completes the ground. Your improvised strap should work fine as taking the whole thing out to clean it runs the risk of some corroded part breaking. You are correct about the tail light and back up assembly being grounded to the bumper. The ground usually fails because the mount bolts for the tail light assemblies get corroded and can no longer supply a good ground. Will need to pull the bumper to fix that one.
Dave
If the "larger plastic piece" that you are referring to is the part that the reflector mounts in, it is pot metal too. The only plastic part on those s/m lamps is the lens, and the reflector. My bet is that the issue is too much corrosion, but the jumper fixed it, so it doesn't really matter.
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