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MG TD TF 1500 - 52 TD Charging/Generator Problems

Just a brief history of this problem Owned the car (52 TD) for about a year, Battery was bad replaced it, then no positive reading on amp gauge, removed generator and found brushes and bracket that holds brushes defective, rebuilt generator w/ Holcomb kit, then installed generator, had to polarize, then amp gauge reads up to + 30 amps with high revs. Replaced voltage regulator thinking that was cause of high amps. After replacing voltage regulator w/ new 5 post Moss unit still get high amps. Tested generator last night w/ John Evans Lucas Test Manual, and generator passes all tests. I stopped short of testing voltage regulator since it is new and I assume that it is working. So my problem is that the charging system is essentially new and still getting high amps when accelerating. Anybody have any suggestions as to where the problem is? Thanks Scott
RSC Scott Cleveland

Is the battery charged? If it is run down, it will charge a lot. You may want to put the battery on a charger, then try driving immedtiately after a full charge. Also, is the ammeter accurate? I thought these generators only put out about 17 amps on a good day. Lastly, never assume anything. George
George Butz

George - Battery is fully charged and check voltage last night it is about 12.5 volts. I have seen other posting about this same problem and others have had similar readings of upto 30 amps - Had not thought about gauge being bad however - Scott
RSC Scott Cleveland

I would still check the new regulator. Things aren't always correct when new.
Dave Braun

I have what seems like not enough generator output to run my TD at night with lights and heater on. I see in the manuals that max amps is set at 17-19 to match safe output of the generator. My lights and heater together draw 15-20 amps and the ampmeter shows -20 at idle and 0 at 2000 rpm If I drive around town at night I run down the battery. I would like to crank up the current setting in the regulator to 25 amps so I can keep my toes warm on these cool nights in Santa Cruz! However, I have seen too many armatures with "thrown solder" from over drawing the rated current. Do the new armatures available have a higher current rating where I could safely set the current regulation up a few amps or do I have to switch to an alternator or keep putting my float charger on after an "evening out". (On the battery, that is)
Thanks in Advance
cj schmit

Chuck, the blower in my Arnolt heater draws less than 2 amps. What are you using for headlights? If you really need that magnitude of power I suspect that you're in the market for one of the modified alternators. Bud
Bud Krueger

Chuck you could use a later generator from a Spridget. I think they are rated at 22 amps.

12.5 volts on a 12V battery, is not fully charged....
12volt car batteries , generally read 13 volts , or more, if they are good. I have had them read 14volts, when new.
Either leave the battery charging, out of the circuit, or check the cells ...You may have a weak one.
A load tester can be used, and are available at most auto-parts stores, who will check it for free.
I don't know if that's the problem, but it's a possibility.
E.B. Wesson

Edward, check the date on the posting. You're responding to something from 2006. Chuck resurrected this posting. Bud
Bud Krueger

Thanks Guys
You were right to doubt my amperage numbers. I was going by the ammeter in my car which exaggerates a lot.
I got out mmy Fluke and found my voltage was set too low. I was only getting 13 volts to the battery so I followed the manual and found i was 2 volts low on the "electrical setting" I set it up to the recommended 16.4 V and what a difference!
I can now have lights and heater on and still stay on the charge side on the ammeter. Even though I know the ammeter exaggerates it still scares me to see it go up to 25 amps when the battery is low. Am I right in understanding that there is no current regulation being done by the "control box"? My old american cars had three coils in the regulator, voltage, current, and the cutout coils. It's my understanding that a generator will overheat and throw the solder if there is too much load. Anyone have this happen??? I'll let you'll know if I have "meltdown"!
cj schmit

Chuck You are right there is no current control in the type of Lucas regulators in our "T" series.

The solid-state conversion does have a current limiter.
Bob Jeffers

This thread was discussed between 11/08/2006 and 06/04/2012

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