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MG TD TF 1500 - Correct Grounding

With the purchase of my TF came several boxes of new parts dating back to the late 80's. The wire loom came from Moss and has no date. My question to the wiring gurus is about grounding. At the rear of the car is several "red" wires that appear to be for grounding. Because these cars are positive ground is that why the wires are red? All of the "fine american" cars I have done the ground wire was always black.
Also...the wires as shown in the attached image have bullet connectors attached. How are these supposed to go to ground? Do I have to make up some kind of bolt-up fitting?

Dan

DHN Nordstrom

You really need to get a shop manual with a wiring diagram. That will show the wire colors and where they go. The wiring in these cars didn't use the traditional positive==red, negative=black system; the wiring for the V+ supply was generally brown, for example.
S Maas

S Maas,

I should have mentioned that with the loom came a diagram that appears to be right from the manual. It just seems odd to me that you would ground "red" wires, especially with bullet connectors attached.
DHN Nordstrom

Ground wires are black, it doesn't mater if you have positive or negative ground - ground is black. Thinking about it any other way will get you in trouble real quick. I am sending you a wiring schematic with the color code. Cheers - Dave
D W DuBois

I'm going from memory, but I think red is usually hot for the tail and tag lights, but that would only be three wires, looks like 4 in the picture. Suggest visually and using a meter and trace them back to origin. George
George Butz

Red in that harness are the hot for turnsignal and brake. Licence plate light is the red and black pair. As Dave D. says...black is ground. Don't ground the red wires unless you want to let the smoke out!

... CR
C.R. Tyrell

Actually I have five red wires. Four with bullet connectors and one bare ended for the license plate light as it is paired with a black wire bare ended as well. I took another look and found the four black wires rolled together as one for grounding. That solves the grounding question. Now what remains is what are the four red, bullet ended wires for? The tail lamps are there and wrapped into another part of the loom.

DHN Nordstrom

The wiring diagram in the manual shows 4 reds into a 4 way connector. This is one live supply and three reds to the two rear lamps and number plate lamp. I crawled under mine and there is the connector. No photo as I have trailer wiring which will only confuse things.I haven't got a clue why they were not hard wired.
Ray TF 2884.
Ray Lee

I scanned the diagram that was supplied with the loom and will attach it here. I see that the same situation appears on the front of the car however there are only two red wires there. I am not up to speed with wiring symbols. Are these symbols indicating a plug or ??? I assumed they were ground. Mmmmmmm

I guess I can't attach a PDF here. Symbols look something like this:


__
____
______
llll
DHN Nordstrom

Well that didn't work. I'll keep trying.
DHN Nordstrom

See photo 206/207 in the "Original TF Gallery". It shows the 4 wires going into a 4 way.
It is great site for detail.
Ray TF 2884
Ray Lee

Ray Lee,

There's my answer. Thank you very much.


Just don't understand why the diagram is indicating a ground symbol. At least I think its a ground symbol.


DHN Nordstrom

This thread was discussed on 08/01/2015

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