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I have a right front fender side marker that isn't working. The socket was pretty corroded, so I cleaned up a better one and I am trying to test it. I see the wiring has a red/hot wire and a black ground, but my question is, does the light itself have to be mounted to and grounded through the body of the car to function?
I have another known working one on another car, but I couldn't find where the wiring from the non-working one unplugs from the car's harness. I was working in my driveway and loosing light.
If you've got a black ground wire, (UK=earth), then this needs connecting to the body somewhere. I doubt the bulb in the light will work without that ground line plugged in somewhere. Where is that somewhere ? Sorry I don't know as the UK cars never had them.
The black ground/earth is connected to the back of the light housing and is then part of the wiring harness that I assume makes ground somehow, but I could be mistaken.
The entire body is the ground. You should have a fat cable that runs from the engine block to a ground on the inner fender in front of the battery. I think the body grounding strap from the factory was down under the car near the transmission but I always just add an additional cable from the block to the fender that way I can easily clean it if necessary.
Then just attach the black lamp wire to the threaded fastener holding the lamp on the fender. Be sure to clean the grounding point down to the bare metal and put some dielectric grease on it to keep it from corroding. And be sure to use a lock washer.
XJ6/12 cars delivered in Australia did not have side markers.
I don't think the English cars had them as my S3 Daimler originally sold in England doesn't have them.
I think it might be a North American specification.
at some point a flashing side marker was introduced in the Series 3 XJ, but in european cars only, on the front wings only, but not for America.
The Series 3 in America used the same static (non-flashing) markers as the MG-B, except the MG's rear Red marker lenses were flatter like the amber front lenses, and more aerodynamic, otherwise identical housing and lens. I fitted those in my '84 XJ-6 as they don't stick out as much.
Car is a 1985 US Spec XJ6.
I like the idea of these flashing, but for now I would be happy with them just working. I tried putting 12 volt power directly to the light, but nothing. I tried to find where the harness disconnects from the main engine harness, but in limited light I have yet to find that. On another XJ6 the pigtail coming off the light was only about 6 inched long, but not sure if the 1985 is the same. I would like to find this and put a test light directly on the harness to make sure the light is getting power. If I put power directly to the light's wires it should illuminate without needing to be mounted to the body of the car where it has its own ground, circled in red.
It could still be a corrosion issue inside the bulb housing. Worst case I could buy a new light from Moss.
Another question. Are the side marker and the front directional connected? It just so happens that the right front directional is not working either, though I have not investigated if it is just a burnt out bulb.
Last edited by MSGGrunt; Oct 13, 2023 at 07:53 AM.
At this point I would strongly suspect the bulb socket if indeed the bulb is OK.
Scrape around until you find shiny metal to connect with the bulb and see if you now have light.
(';')
yes, it could be the socket corroded inside per Elinor.
Also if you pull the red wire, does it spring back ? The bulb is supposed to push the spring down to remain tight in place.
if yes, is the bulb itself the correct one ? Have you tried a bulb from the ones that light up ?
the brass ground tab is very thin and delicate in these assemblies, originally the black wire from the harness has a bullet end and it is inserted into the ground tab so the tab must be formed to accept the bullet tightly.
If no bullet end in the ground wire, it is best to solder a new wire to the tab, then make a "disconnectable" connection elsewhere after the new wire.
the rear ones are easier to deal with. Remove the 4 tail light lens screws, remove the 3 big tail light housing screws, pull the housing and you can see the wiring harness plug and the marker wires. Very simple assembly.
Replaced the fuse and both lights are now working. Next up, no reverse lights. This time I will check fuses first and maybe a switch adjustment for these.
Replaced the fuse and both lights are now working. Next up, no reverse lights. This time I will check fuses first and maybe a switch adjustment for these.
If your instruments and trip computer are working the fuse is OK; the reverse lights are on the same fuse.