> While driving the wife to work today in beautiful topdown weather
> all of a
> sudden the ammeter stopped indicating charge and the red light
> came on.
Ok, just because sometimes we overlook the obvious : Did you try to shake
the generator on it's mounts ? Double check the belt tension ? Visually
inspect the wires to be sure they are securely connected at both ends (tug
on them a little) and not shorted to anything (including each other) ?
> I
> suspect its the regulator (control box) since I'm getting no
> output to the
> yellow wires,
That's actually the way it should work, if the generator was bad, so it
doesn't mean much. The red light tells you directly that there is little or
no voltage on the D terminal, and the F terminal is connected to the D
terminal so there's nothing on it either.
> unless I push the points together manually, then
> the light goes
> out and the ammeter goes neg. all the way. (I'm in a neg grd
> situation.)
Are you saying that the ammeter connections were not reversed when the
conversion was done ? 'Negative' should always mean discharge, regardless
of ground polarity, but the leads to the ammeter should be reversed when
doing a conversion, to maintain this relationship.
> I
> have no meters to check anything as recommended in all the manuals.
Well, why not ! Harbor Freight has a cheap digital meter that is frequently
on sale for only $10, less than the price of almost any electrical component
on a TR, that is plenty rugged enough to ride around in the trunk. I carry
one all the time in the TR3, as a talisman against Lucas, Prince of
Darkness.
http://www.harborfreight.com/cpi/ctaf/Displayitem.taf?itemnumber=33499
And at that price, if it does get busted, it's no great loss.
> My
> tendency is to replace one thing at a time.
Not always a good idea here, since a bad regulator can cause a good
generator to fail fairly quickly.
> Must I remove the
> generator to
> take to a shop to test it,
Most shops these days have no idea how to test beyond what you've already
done. The red light on the dash means it's not charging, which is about all
they can tell you. However, if you can find a shop that is familiar with
generators, they should be able to test it on the car.
> should I drive it to the shop to test,
There's no reason you can't drive the car for limited distances with the
generator not working. In fact, if you have a way to charge the battery
when you get home, you can go many months by just recharging the battery at
night (BTDT).
> can it be
> tested in the car if the regulator's not working?
Yes.
> What could make the
> control box go bad all of a sudden?
Short answer : they do that. Because of the way it works, it's usually an
"all or nothing" thing when they do fail.
> Or maybe it's the generator?
Could well be.
> Maybe it's
> both?
Also entirely possible, in a number of ways. The one I've had the most
experience with, is the control box allowing too much charging current,
which overheats and eventually ruins the generator. If the winding on the
cutout relay opens (so the contacts don't close) or the cutout contacts
fail, the generator can generate too much voltage and ruin it's own
insulation.
> What to do first?
Figure out which direction your ammeter reads for discharge. If nothing
else, turn the lights on with the engine off, and note which way the needle
deflects. Now remove the wire from the 'F' terminal at the control box, and
temporarily connect it to the 'D' terminal. (BTW, a set of 'clip leads'
from Radio Shack is real handy for this sort of thing, I also recommend a
few of them to carry around with the meter.) Start the engine, let it idle
(don't rev it up) and see if the red light goes out. If it does, the
problem is very likely the control box (although the generator could
possibly still be bad). If it doesn't, then try mashing the cutout contacts
closed as you did before and observing the ammeter and red light. The red
light should go out, if not then either the control box is really bad, or
there's a problem in the wiring. If the ammeter now reads charge, once
again the problem is likely to be the control box. If still no charge (and
the light is out), then the generator, or the wires to it, are the most
likely suspects. If you get only a weak charge at this point, rev the
engine up to about 1500 rpm. If the charge is still only a few amps, then
the generator is likely bad.
There are some more tests that can be done with a test light, but do what
I've outlined and report back here first.
Randall
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