[TR] tr3 generator woes

[Randall]

> at idle the amp meter read that the generator was pushing 15 amps back (+)

That alone seems very odd to me.  There is some variation, and of course two
different units fitted as original; but I've never seen a stock TR3
generator that could put out 15 amps at idle.  Are you sure it was charging
and not discharging?

> i didn't think the tr3 generator was capable of putting out 35 amps? i
> guess im wrong?

It can do it, but not for long!  The control box should limit the flow of
current to well under 35 amps even right after starting.  It can go a little
higher than the rated current (either 19 or 22 amps, depending on whether
it's the earlier C39 or later C40 generator) for a minute or two, but any
more than that risks overheating and damaging the generator.

Even with a heavily discharged battery, the voltage should quickly rise to
where the control box limits the current.  But it is possible to have a
shorted cell and still start the car.  That can lead to overcharging and
again can damage the generator.  So IMO it's wise to keep an eye on the
ammeter, and if you should see more than 20 amps (the ignition draws 2 or 3
amps) for more than just a minute or two after starting; stop and
investigate.  If necessary, shut the engine off, pull the wire off the 'F'
terminal, and drive home without the generator.

Worth noting that continuous overcharging can also damage the rest of the
car.  An overcharged lead-acid battery generates an explosive mixture of
hydrogen and oxygen (that "boiling" you see in the electrolyte is actually
water being converted back into it's component gases).  If a spark happens
or something gets hot enough, the mixture can explode, blowing the battery
apart and even setting fire to the car!

I'll never forget some stranger knocking on the door and asking "Did you
know your car was smoking?"!  Although in that case, it was a non-LBC with a
shorted battery and a home-made battery charger.  Fortunately I got the fire
out before the damage was too severe, but it burned the paint off the hood
and ruined nearby hoses & wires.

> first thing is to get the in line fuse out.

Yeah, the fuse is a bad idea, IMO.  If it should blow, most likely the
generator field will remain connected to the battery (through the cutout and
regulator relays), so the output voltage will go very high and, very likely,
ruin the unit.  Just like with current, the generator is quite capable of
developing enough voltage to ruin itself.

Although perhaps not necessary, I think I would disassemble the points on
the regulator relay for inspection and cleaning.  IMO this is a periodic
maintenance item every 10 years or so (even though again, the book says
leave it alone).

Right after that, I would check and adjust the contact gaps for both relays
in the control box, followed by adjusting the tension on the regulator
relay.  The book claims these adjustments are made during manufacture; but
no manufacturer has been doing that for a long time.  So even brand new
units need to be checked and (usually) adjusted.

As a side note, the TR4 workshop manual gives an easier alternative to
disconnecting the wires from A and A1.  Instead, leave the wires connected
and place a piece of paper or thin cardboard in the cutout contacts.  I find
it helpful to tear it into a rough "U" shape so it stays in place easier.

If it still doesn't act right; try the troubleshooting steps given at
http://tinyurl.com/hu23223

-- Randall