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MG TD TF 1500 - Question About TD Charging

I think I am having some electrical issues with my '53 TD electrical system. After starting the car the ammeter indicates the generator is charging at lower RPMs. As I increase the RPMs above 2000, the ammeter starts to jump around quite a bit. Is this this an indication of the regulator cutting in and out, the generator not function properly or is this a common situation experienced by other TD owners? I'm leaning towards a problem but wanted to pick other peoples' brains before getting too carried away with tearing things apart. Thanks for your thoughts!
A. R. Todd

Have you tried cleaning the points in your regulator? If that doesn't clear it up, check the brushes in your generator. There is a problem but it's fairly minor I believe.

Gene
Gene Gillam

Wouldn't hurt to clean the points as Gene suggests. My needle is sort of quivering at higher revs, always has been. It also flicks when the fuel pump ticks, which of course happens more often at more open throttle. If your battery stays charged and doesn't run down with lights on, not a real issue. George
George Butz

I just got back from a three day 550 mile road trip throughout the Blue Ridge mountains. Today I realized that the car was not charging. I turned off the running lights and I kept it running most of the afternoon to get home, got it in the garage, shut it off and it was so dead that the horn wouldn't even beep softly. I put it on the charger for a bit and got it running, checked the generator and realized that it was not passing any juice to the battery. I simply cleaned the voltage regulator contacts and it charges great. The needle does indeed jump around a bit. It has been that way for years with no problem up to now. If it works, then I wouldn't mess with it as long at it charges okay.

Mark
Mark Strang

Thanks for the thoughts, guys. I did clean the contacts this afternoon and was about to take a test drive but got interrupted so I'll test drive it tomorrow. The one thing that has bothered me is the degree to which to needle jumps at higher RPMs but we'll see tomorrow. Generator brushes might be the problem. I'll check those tomorrow as well. It only has about 17K miles since a total frame off restoration but that was 25 years ago.
A. R. Todd

A,R.,

My experience with two 1953 TDs over many years is that the ammeter is jumpy except for a brief period just after start-up when it is in a fairly heavy charge mode. Lucas voltage regulators (original or equal) are very reliable. Clean points and good generator brushes are a given. Good luck!

Jim Haskins 1953 TD
J. M. Haskins

Most ammeters have some degree of damping, but the TD ammeter seems to have very little. If it twitches a bit, I wouldn't worry about it--it's just responding to the regulator clicking in and out. As long as you are seeing a charge at modest engine speeds (say, above about 2000 rpm) in normal running, I wouldn't worry about it.

If you are still concerned, though, cleaning the regulator contacts is not a bad idea, as long as you do it right. It's generally not a good idea to use sandpaper, as bits of silica can end up embedded in the contact surface and prevent good electrical contact. That leads to more sparking and burning of the contacts. My favorite tool is a special contact cleaning file, which you can get from an electronics store. It's a metal wand with diamond dust in the surface, like a knife sharpener. If you can't find that, just use a piece of paper and gently hold the contacts closed on the paper as you pull it out from between the contacts. Do that a couple times.

It is ESSENTIAL to disconnect the battery when you do this.
S Maas

This thread was discussed between 24/09/2015 and 25/09/2015

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