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MG TD TF 1500 - Ignition Light Issue

Greetings and Happy New Year!
I had the radiator house blow on my TF1500, while under power and it spewed fluid all over the electrical components. Dried everything, fixed the hose, replaced plugs, checked distributor wires, belt is correctly tensioned, and took it for a drive. The car is still missing and now the ignition light stays on, the ammeter is middle to slightly negative. I disconnected the battery while running and the engine stopped immediately.
The radiator fluid probably caused a short so now where do I look first? Generator, volt meter....
Appreciate any guidance?
Thanks

Tim Moylan

Generator....
Gene Gillam

Tom - As Gene states, you have a non functioning generator, probably full of coolant. If you are not into overhauling a generator, I would suggest that you look up an auto electric shop and take the generator to them for a complete overhaul. Cheers - Dave
D W DuBois

You might try to take it out, empty it and dry in a warm place, that may be enough. Worth the try before you bring it to a shop.
Works most of the time with computer keyboards;-).

It might also be a problem with the regulator, which probably did not get soaked but maybe suffered from a short in the generator. Dave, as the regulator expert, may be able to suggest the best way to test.
Mike Fritsch

Before I pulled the generator, I'd check that it has not lost its polarity when/if it got wet. Lots of info on this easy check/fix in the archives.
L Karpman

All this is just a wag but wouldn't the easiest test be to just re-polarize it. If it has not lost its polarity I'd think this wouldn't hurt anything. Jud
J K Chapin

I found the threads on testing polarity and for general testing the generator and regulator. On it tomorrow and will let you know. Thanks for your feedback.
Tim Moylan

I repolarized the generator (arched the a and f posts on the regulator with a screw driver which showed a spark) but it didn't work; engine still misses and shuts off when I disconnect the battery. I tested the generator and no spark is present (touched the f and d wires from the regulator) therefore I am looking for local shop to rebuild the generator or trying to find a rebuilt/new one.
Tim Moylan

Should not be too hard to find a shop that can re-build these generators. Any Auto Electric should be able to do it. If you have trouble finding one, try calling a local tractor/Ag dealer, and see who they use. There are still lots of tractors out there that use Lucas generators. Just remember that The T series have a tach drive.
...CR
C.R. Tyrell

A generator really should not need to be rebuilt just because it got wet. I'd suggest rinsing out the commutator area with clean water, then dry it out as Mike suggests. If that doesn't fix it, check the brushes' connections and make sure they're clean and tight. You can check the generator by connecting the field and dynamo terminals together, connect a wire to the battery, and see if it runs like a motor. If it does, it's probably OK.

Also be sure that the regulator is OK. The shop manuals have procedures for checking it.

People tend to overestimate the effect of electrical things getting wet. Usually, if you dry them out well, and the water is clean, it's no big deal.
S Maas

Now the car won't turn off!
I installed the rebuilt generator, polarized it and the car started right up (with a very faint ignition light). The dashboard dial shows positive at 5 which is higher than normal. Drove the car for 10 miles, pulled in the garage and it wouldn't turn off. Disconnected the battery terminal and it didn't shut off so I pulled the A and D lines from the regulator (still didnt shut off), but then disconnected the battery and it turned off. Any suggestions?
Thanks, Tim
Tim Moylan

My suggestion is check your wiring. Logic dictates that the feed from your battery -negative pole-is bypassing the ignition switch.As the only thing that has changed it implies a polarity problem.Is it now negative earth and not positive?
JK Mazgaj

This is exactly what happened to me some time back, I had not touched the wiring or any electrical component but I did connect my battery charger with the voltage switch to 6 Volt instead of 12 volt.
I took the leads off the Generator and polarised the system as per instructions found here, it worked and have had no more trouble, my car is Neg earth.

Regards

George
G Mills

Tim,

Check your fuses carefully. It is easy - especially in dim light - to slip the fuses into the wrong place between the prongs rather than inside the prongs (if you catch my drift). If that happens the horn fuse (hot all the time) will power the ignition (normally switched).

Good luck,

Jim
J Barry

Hi Tim -

This is a shameless hijack of your thread ... Hope to see you at GoF South, April 17-19.

Events, registration, resort information
http://www.gofsouth.com/

By the way, I didn't go to GoF last year (my first) because the generator in my TF was not working. Good luck with yours.

These links may help:

> Lucas Generator and Control Box Tests
http://mgaguru.com/mgtech/books/pdf/Lucas_Generator_and_Control_Box_Tests.pdf

> Lucas Overseas Technical Correspondence Course: Section 4 - Generators
http://www.fromtheframeup.com/uploads/Lucas04_Generators.pdf

> Lucas Overseas Technical Correspondence Course: Section 5 - Generator Output Control
http://www.fromtheframeup.com/uploads/Lucas05_Generator_Output_Control.pdf

> The complete Lucas Overseas Technical Correspondence Course
http://www.fromtheframeup.com/Lucas_Manual_CTYJ.html

Lonnie
TF7211
LM Cook

Following along on Jim Barry's comment, many of us don't know that if you lose the ignition key, or have more esoteric ignition problems, it's worth trying to pop a fuse between the prongs to get the ignition going. I saved a long tow for a TD once with this little bit of knowledge.

David
D A Provan

Thanks to all for your advice. Jim wins the Prongs for $200 question! I rechecked all the wiring and fuses and must have placed the a1-a2 fuse outside the slot vs. inside. Moved it and now the TF is running very nicely. Thanks and happy motoring.
Tim Moylan

Ah Ha... So there was a reason for all the aggravation that little mistake caused me! Glad to have helped.

Jim

J Barry

This thread was discussed between 06/01/2015 and 16/01/2015

MG TD TF 1500 index

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