MG-Cars.info

Welcome to our Site for MG, Triumph and Austin-Healey Car Information.

Parts

MG parts spares and accessories are available for MG T Series (TA, MG TB, MG TC, MG TD, MG TF), Magnette, MGA, Twin cam, MGB, MGBGT, MGC, MGC GT, MG Midget, Sprite and other MG models from British car spares company LBCarCo.

MG TD TF 1500 - TC Generator

I would place this in the TC section, but nobody reads it. The green TC did not charge on the way to the GOF in Middlebury. The battery died at the GOF, and the car came home on a truck. I was not able to get any charge out of the generator. It looks to have been recently overhauled. I could not find anything obvious, like burned wires, mechanical failure or bad brushes.
Any spark guys have any suggestions on where to go next? It is sitting on my work bench, waiting for me to figure out what to do next.
David
D. Sander

Check the contacts in the regulator (with the battery disconnected, of course). Most of the non-functioning charging systems I've seen get their regulators replaced when all that would be required is a simple cleaning of the contacts in that regulator.
Lew Palmer

I tried to clean the contacts in the regulator. They were spotless. I followed John Twists video for testing, I could not get anything from the generator. I removed the wires from A and F (?) and shorted them, no spark. I tried to polarize it too, still nothing. I checked the wires for continuity, and no issues found there.
I quit when I realized I was to tired to think.
D. Sander

Dave:
Oh go ahead and post on the TC board....we need some new posts. However, as to your problem - I would check to make sure your grounds are good...also clean the battery posts. Then disconnect the battery from the car ( remove the post clamps) and give the battery a good charge. Then check the battery, should read about 12.7 to 13 volts if good. If the battery doesn't pass muster work backwards and check generator output. You may just need to clean the commutator and brush gear of oil and varnish.

Brian W.
ZBMan

To test the generator out of the car or in the car with the fan belt removed and the wires to it disconnected:
1. Connect the two terminals together with a short piece of wire.
2. Connect the -ive from a battery to one of the terminals.
3. Connect the +ive of the battery to the case (gnd).

If the generator runs like a low power motor it is OK.

H.D. Pite

Hugh,

That's a great trick. Simple and should point directly to the main problem.

Should apply to all generators.

Gord Clark
Rockburn, Qué.
Gordon A Clark

David,

The TC site is seldom used on this forum because we have a complete site dedicated to the TA's, TB's and TC's.

www.mg-tabc.org

In addition to the forum located there, there's a very active Yahoo email forum for site members (site is free).

Best regards,
Gene
Gene Gillam

Hugh's suggestion will test the integrity of the generator, but if you are running negative ground, it will likely repolarize the generator the wrong way. If you are running positive ground, his suggestion if fine.
Lew Palmer

I tried Hugh's suggestion. The generator did not turn, but did turn slowly when I started to spin the pully. It turned very slowly, and the movement was jerky. When I stopped it with my hand, it would not start again.
David
D. Sander

http://www.dynamoregulatorconversions.com/field-coil-testing-and-winding.php

http://www.mg-cars.org.uk/imgytr/pdf/lucascourse4.pdf
Some good info starting pg. 21 how to test, etc.


Certainly no expert, but make sure brushes are not worn out, the springs are good, and nothing is visibly broken or shorted/burned. George
George Butz

David, I once had a similar problem and it turned out to be that there was too big a gap between one set of points in the regulator. When the car is not running, one set of points should be closed and the other set should be open. When the engine is started, the open set should close if the generator is OK. Do NOT manually close them when the engine is not running as they will stay closed and burn something out! I manually closed the points with the ENGINE RUNNING at about 2000 rpm? and found that it charged correctly but when I stopped and restarted the motor the problem was back. I then reduced the gap (which also reduced the gap the electromagnet has to work through) and the problem was fixed. It was a long time ago so I hope I have remembered the details correctly. Check with others before trying this. However, I would strongly recommend leaving regulator adjustment to a expert because of the chance of burnt wiring or setting incorrect charge and cut-out levels. Bob Schapel
R L Schapel

What about the generator brushes? Seems that would be the first and easiest thing to check if the generator isn't charging.
Gene Gillam

Hi David,
check www.healey6.com/bulletin it will give you all the info you need to check/repair your dynamo.
Ray TF 2884
Ray Lee

This thread was discussed between 24/06/2014 and 25/06/2014

MG TD TF 1500 index

This thread is from the archives. Join the live MG TD TF 1500 BBS now