In a message dated 4/24/99 9:41:48 PM Eastern Daylight Time,
steve@mindtribe.com writes:
> I could use some help with an ammeter problem--it's been driving me nuts for
> months! The (new) alternator in my TR6 puts out about 16 volts at 3000
> engine rpm. The manual states 14-14.4V should be seen on the output
> terminal. This sounds like a regulator problem?
Steve,
Yes, this sounds very much like a regulator problem. At 16 volts, you run the
risk of battery damage, and a shortened life of all the light bulbs in your
car.
> My ammeter jumps around erratically when I drive, all the time. I have done
> some debugging, including removing all fuses (thus isolating the
> ignition/charge circuit) and the problem persists. I'm guessing that my
> regulator is bad, allowing voltage to increase until a cutoff is reached
> around 16V, then drops to zero, and starts repeats this rapidly. However,
> I've sent the alternator to the remanufacturer, they tested is "for several
> hours" and claim it looks OK.
The regulator in the alternator is an "on-off" type, rather than a continuous
adjustment, but the on-off cycle is usually to fast to show up on a voltmeter.
> Here's what happens:
<snip>
I can only think of two things that might cause the symptoms you described: A
faulty regulator of a bad connection in the wiring somewhere. Bad connections
are always more or less random in nature, or, if not, very definitely tied to
movement of some sort with respect to the connection -- rocking of the
engine, hitting a bump, etc. Given the very consistent and repeatable nature
of your problem, I can't see any thing that could cause it from a bad
connection. I'm certain that your regulator is faulty.
You might want to take the car to the alternator dealer and have him monitor
the voltage in the car. If he claims it is another fault, make him explain
what it is. If it should turn out to be something other than the regulator,
please let me know, so I can add the information to my databank.
Dan Masters,
Alcoa, TN
'71 TR6---------3000mile/year driver, fully restored
'71 TR6---------undergoing full restoration and Ford 5.0 V8 insertion - see:
http://members.aol.com/danmas/
'74 MGBGT---3000mile/year driver, original condition - slated for a V8 soon
'68 MGBGT---organ donor for the '74
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