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MG TD TF 1500 - TD charging problem-I'm stumped

Hello All - my first post, and I'm badly in need of help.

Long story, but contains all the facts. Late last year my 51 TD started to hav echarging issues, so I decided to install a solid-state unit from Wilton Elect. When i installed it it ran fine for a couple minutes, then POP. 3 electrolytics blew up. I wrote to Mr Jeffers and he said he'd had a bad batch of caps. Return it and he'd fix it.

When I installed the fixed unit all seemed working but after 15 minutes driving the ammeter would swing wildly from 0- +10 amps. This continued for a couple months driving.

This year when I started it up for the first time the ignition light was on full and I was getting no charging, although when I turned on the headlights I did get a discharge reading, so the ammeter is not at fault. I installed a new rebuilt generator - no change. I sent the regulator back for a second time and was told he found some "things" and sent it back.

This time the ignition light glowed but decreased brightness as revs increased to 4k but never completely went out, plus still no charging. But then, for no aparent reason, everything started working - for a week.

Unit was returned for a 3rd time, more repairs were made, reinstalled the reg but still no charging.

I just got in from having my wife rev the engine while I fiddled with the wiring, thinking that the reason it started working spontaneoulsy was because of a wiring fault - nothing.

Any and all thoughts cheerfully entertained.

Lani Spahr in Ardmore,PA
L Spahr

Lari, years ago I had somewhat of the same problem. It turned out the Generator was shot. The windings were melting the solder in the gen and it would send the ameter needle bouncing all over, lights would not work right and it ran kinda funny. Took the Gen it to the folks here in mpls and it was the generator and the regulator both were shot due to the gen going out. You might want to check the gen by taking it apart and inspecting it. just my opinion.
Tom Maine (TD8105)

Thanks Tom, but the wild swings are gone since I installed a new generator. But i still have no charging.

Lani
L Spahr

have you Polerized the generator ??
Gerard Hengeveld

Not sure what you mean, but if you mean do I know that the generator is POS gnd like my battery, yes it is.
L Spahr

http://homepages.donobi.net/sufuelpumps/Other_Subjects/Electrical/General/Polarity_Change.pdf


Excellent description...
Gene Gillam

Not sure what this has to do with my situation.
L Spahr

Lani,

Gerard's question above is significant. Polling the generator, some call it flashing the field coils, established the magnetic field that allows the generator to achieve full output in the polarity of the system in which it is installed. The archives contain instructions and the task only takes a few seconds once the bonnet is open. Costs nothing and worth the effort.

Regards,

Jim Haskins

1953 TD
J. M. Haskins

http://www.mossmotors.com/Shop/ViewProducts.aspx?PlateIndexID=37873

Click on the link: how to polarize generator and how to test. If you didn't polarize it when installed, it likely won't work. George
George Butz

OK, getting closer. I looked at john twist's youtube video and it appears that my generator isn't working. I sparked the dynamo then He says disconnect F & The bigger D wire and they should spark. They don't. Just to make sure it's not a bad wire I disconnected both wires from the dynamo and shorted the connectors together. Nothing. No spark.
L Spahr

OK, getting closer. I looked at john twist's youtube video and it appears that my generator isn't working. He says disconnect F & The bigger D wire and they should spark. They don't. Just to make sure it's not a bad wire I disconnected both wires from the dynamo and shorted the connectors together. Nothing. No spark.
L Spahr

Make sure which D wire you're scratching with the engine running. You want to touch the F to the D wires coming from the Dynamo, to see if "self excites" and makes voltage.

If you have the F & D wires loose from the generator, use a meter to see if there's continuity to ground. Both should show low resistance to ground. You would be better off checking the field and armature right off the generator with the wires disconnected, so you can really test the generator and eliminate diabolical wiring issues.

If you don't have access to a meter, hold a wire on your battery "hot" terminal, whichever is not the ground, and scratch it on the generator terminals to see if there are any sparks.

Then report back to us, please. It is always a pain when the owners with problems fail to reply and then we never know what worked, if anything and what was the problem.
JRN JIM

Thanks everyone for your help. I'm not there yet but getting closer, i hope. After not getting spark from the dynamo i reinstalled the original one. I had replaced it on the suggestion from bob jeffers. It worked for a week and then i was back to the original problem. Noew with the original dynamo i do get spark, but still no charging. I've ordered an original voltage regulator to replace the solid state one. With everything that's gone on, i don't trust that it's working properly. When i install the new regulator i'll report back. Thanks everyone.
L Spahr

L Spahr wrote:

"Not sure what this has to do with my situation."


Actually, neither do I...grin. I was mixing emails with forums and got lost with my cutting and pasting. Sorry...

Hope you get it fixed soon.

Gene

Gene Gillam

Spring update. I ultimately ordered a new stock voltage regulator and installed it with my new dynamo and I'm happy to announce that I now have a working charging system! I assume that, although I can't say with 100% certainty, that it was the regulator all along. Now, as to why the solid state unit from Wilton never worked? I don't know, but I do know that after it worked for a while and then blew up (bad caps) it never worked after that, even after being returned for repair twice. I wonder if the owner of Wilton reads here?

Anyway, I'm back on the road (with newly installed turn signals). Many thanks for everyone's help. You all are a marvelous resource.
L Spahr

L Spahr Send it back and I'll put a new board in it.
Cheers,
Bob
R. K. Jeffers

This thread was discussed between 29/07/2012 and 27/05/2013

MG TD TF 1500 index

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