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MG TD TF 1500 - New Wireing and Generator troubles

Hello again everyone. I finally have my TD registered and have been making short trips around the block to see if everything is working ok. I tried my first night time trip last night and noticed that the sidelights caused the ammeter to go to hard discharge....OK short somewhere. Discovered that the license plate light was wired backward. Fixed that and now my generator seems to have stopped working! It was working fine before tonight, albeit with some large readings, not surprising, as the battery is probably somewhat discharged from quite a bit of electrical testing with the engine off. Ammeter seems to sit at 0 and twitch regularly....Any thoughts would be gratefully accepted.

Photo of the completed product attached.


J.D. Hine

J.D. I can't help with the non charging but the twitch is caused by the fuel pump working.Was the generator charging okay before the light problem?
Sandy Sanders

Reset the generator field by repolarizing the generator. Can't hurt to try. Archives have the procedure. Takes only a few seconds to do.


Larry Karpman

Don't see any photo Joe but the first thing I'd do is re-polorize the generator and go from there.


Careful about grounding the license plate light...when I repainted my bracket, it was grounding through the wires...had weird things happening between lights/brake light... had to take the bracket apart and scrape off paint at each connection.
gblawson - TD#27667

J. D. Hine Remove both wires from the generator and jumper them together. Put a voltmeter between the jumper and the case of the generator. Start the engine and carefully bring the rev's up while watching the voltmeter. The voltage will quickly go up to 20 volts, stop there. The generator is OK if you get the 20 volts.

You can also check the polarity of the voltage to insure that it is the way you want it, positive ground or negative ground.

I don't think repolarizing the generator will do anything because the generator will run into a direct short with no problem. Because when there is a direct short the field excitation is removed. With my generator running into a direct short there is 1 Amp of current in the wire shorting it.

Keep us informed of your progress in finding and fixing the problem.
R. K. (Bob) Jeffers

This thread was discussed on 06/09/2007

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