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MG TD TF 1500 - Lucas 1130 light problem

Hi Guys,
My right front parking light gave up the ghost last week and I finally got around to looking at it, all apart. I have a single filament light, lucas 1130 that is original to the car and no doubt about it the socket is original. When I took it all apart there are two wires going to the light. One is a bullet connector into the socket and the second is a green wire capped off. Where is the ground? There is not even a place to hook up the ground wire. I have power going into the wire that goes in to its bullet connector. When I hooked it back up after cleaning everything down to bare copper and no corrosion, ...no light. I have a new socket from Moss but there are two bullet connectors on the back side of the light socket and a ground connector on the bottom. So how do I hook this new socket up if it is a socket problem with the old part? Where do I run the ground wire from? The other capped off green wire has power also, but I don't have turn signals so I am not going to use it. I suppose someone put a new harness in a while ago and it had the dual light wire harness. Why did the original light never appear to have a ground wire, was the bolt securing the light to the wing the ground?
I can fix almost anything on this car and have done most of it, but electricity always stumps me. The transmission and engine were a piece of cake compared to the electrical stuff on this car.
Cheers, Rob
Robert Silverman

Rob - The problem you are facing is the same one that causes dim headlight for so many of our cars. The ground is through he mounting screw to the fender. When you think about this, you will see all sorts of problems associated with it, mainly every fastener in the string from the light socket to the ground side of the battery, each one of them a source of a high resistance connection as a result of corrosion at each joint. I have the same situation on our TD and intend to correct it this summer (I spent 40 years working in the electronics trade and just recently realized what I did electrically when restoring the car, so don't put yourself down about not being good with things electrical). My intended fix on our TD is to run a dedicated ground wire from the frame of the car to each headlight and side light, a project that is somewhat daunting in that it requires running a new wire in the existing harness to each fender and then splitting it off to the head light and side light on each side, but the result will be a positive ground for the headlights and side lights that doesn't depend on at least three bolt and nut connections of sheet metal to sheet metal bonds to carry the current. Good luck - Dave

PS - If you decide to do this, or just want to clean up the existing connections, see my article on ground point preparation at: http://www.omgtr.ca/technical/General%20Technical/grounding.htm
Applying this to each connection joint, should restore your side light operation.
David DuBois

Rob- wiring is like circulation. To over-simplify but hopefully make sense- The "hot" side (negative, if positive ground) is like the arteries from the heart, and the ground is like veins, returning. They have to connect all the way around. Try touching a wire to a good ground (the battery post) and to the outer bulb housing and it will light. David is correct- when new, there was not 50 years of paint, crud, undercoating, etc., so they got away with grounding through the fender. George
George Butz

Thanks Dave and George,
I am off to make a good ground connection then tune up the beast and get it inspected this week.
Cheers, Rob
Rob Silverman

This thread was discussed on 15/05/2005

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