I bought one of Dave’s side-marker conversion plug kits from MSA and have installed both the headlight relay kit and parking light relay kit.  Both of these were very straight forward and installation was pretty much a plug and play affair.  Now I am working on the side-market conversion plugs (SCP) and having an issue getting the side-marker housing isolated from the body.  The instructions say to use an Ohm meter and see if the black wire going from the housing completes a circuit to the body.  I encountered a complete circuit tone so I widened the holes in the housing and put some electrical tape around the back of the housing and tried again.  Once installed I continued to get a complete circuit to the body and after moving it around some I had no success.  With the housing unscrewed from the car and hanging out I continued to get the tone from my ohm meter and discovered the only way I get break the circuit was to unhook the green power wire going to the side marker.  The green wire must stay hooked up to the car for everything to operate.  Unfortunately with the new plug installed, once you connect the ground for the housing to the ground of the plug it turns on all the lights on the car (headlights, turn signals, and markers) Pull the ground out, everything turns off.

 

So I am stumped, what I am missing here?  All of the lights work properly as-is.  The housing has to have its green power going to it but I can’t figure out why the ground for it continuously closes the circuit to the body when the housing is not touching the car.

Its possible the mounting screws are contacting the metal lamp body on their way to the fender.  Check that the rubber seals are carefully fitted to the lamp body and the screw holes in the seal are not close to the lamp body holes.  Then carefully fit the lens and stainless trim into the seal but don't change the seal fit on the lamp body.  I have this kit and love the effect on the marker lights.

The mounting screws for the side marker lights were an issue on my car.  I had to drill out the mounting  screw hole slightly in the lamp body on one light.  I think it ws a aftermarket replacement lamp that had the problem.

 

John

Thanks for the responses guys.  Unfortunately I don't think I am being clear.  Even with the marker light handing off the car and none of the housing touching the body I still get a complete circuit tone.  The only way to make it stop is to unhook the green power wire going to the bulb.  In my understanding of automotive electrics this should not be happening as it appears the wiring for the marker light circuit itself is also providing a grounding circuit.  That should result in a short but everything functions properly.  Any other ideas?

That is odd, I have to ask because you refer to a single side marker. Is the other side hanging out with the black wire disconnected as well or is it still all hooked up?

Good question 240.  Yes, the other side is still mounted on the car.  In the post above I was working on the passenger side front marker light.  The driver side had not been removed.  Do you that is possibly causing the complete circuit?

They are both on the same circuit, so I would hook up the side marker plugs to both sides and try it. I use the side marker plug as well and have had no problem with it.
Dan

I messed with it some more today.  With both the driver side wires disconnected and only the green wire hooked up on the passenger side I still get a closed ground circuit on the black ground wire of the passenger side light.  When I hooked up the SLP on the passenger side and connected the ground to it the headlights came one.  I just don't see where else it could be grounding out.