[TR] TR4 generator failing

[Randall]

> Would someone be so kind as to describe a simple voltage test that I
> can
> conduct at the generator, so I can be certain I have that right?

Based on the tests I did on my TR3A many years ago, what you saw is actually
at least close to being normal.  The TR4 generator is only rated at 21 amps,
and I measured the actual load at about 22 amps with the ignition, heater,
wipers, and lights.  Plus of course, the generator only puts out maximum
current when turning fairly rapidly, over about 1500 engine rpm or so.  At
lower speeds, it won't keep up and the battery runs down even faster.

Once the cutout has closed (putting out the red light), the voltage at the
generator should be exactly the same as the battery voltage (since the
cutout relay connects them together).

So, for a simple OK/NOT OK test, I would suggest running the engine at a
fast idle (1500 rpm) and using an accurate voltmeter to check the voltage at
the battery.  With the lights and such off; and the battery reasonably well
charged, you should see about 14.4 volts.  Now turn on the headlights and
other loads, and check again.  If the voltage drops below about 13.0, you've
got a problem.

FWIW, mine improved noticeably after I removed the moving regulator contact
and cleaned both it and its mate in the control box thoroughly with a point
file.  Then when I reinstalled it, I was careful to set the gap as the book
specifies.

But it still won't keep the battery charged when running around town (or
heavy traffic) at night.  I'm probably going to go back to running an
alternator.

Oh, one other point, the generator and control box work very closely
together.  If the generator is working at all, it's up to the control box to
limit the current, as otherwise the generator will happily put out too much
current for too long, overheat and destroy itself.  I learned that lesson
the hard way, many years ago.

-- Randall