Generac 7500

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Ellombris-

NO. When the field needs to be flashed there is no output at all. If
there is ANY residual magnetism, there will be output, and almost
instantly it will build up to full value when you start the generator.

Something else is causing your problem.

Could it be the Idle Control switch is set to the "ON" position? That
would give your symptoms until you connect a load to the generator
output. If you connect a light bulb to the generator, does it light to
full brightness, or barely at all?

The diodes that rectify field current are in the module you replaced.
Unless it has an open diode, it is unlikely to be the problem.

When you installed the module, could you have connected the wires to the
brush assembly backwards? According to the Clymer manual, the White
wire connects to the positive brush, which is the one closest to the
bearing.

Fred

I removed the brushes and seated them properly, it seems they were
already seated OK. Changed the wires to the brushes opposite to how
they were hooked up, got 0 voltage. Reversed them and I get 65vac @
the 120 outlets and 120vac @ the 240 outlet. There's nobody local, but
I'm gonna try the closest to me, about 50 miles away that supposedly
works on generators. Otherwise this unit will be on sale on E-bay as is
to the highest bidder.

 

[Ken Weitzel]

I removed the brushes and seated them properly, it seems they were
already seated OK. Changed the wires to the brushes opposite to how
they were hooked up, got 0 voltage. Reversed them and I get 65vac @
the 120 outlets and 120vac @ the 240 outlet. There's nobody local, but
I'm gonna try the closest to me, about 50 miles away that supposedly
works on generators. Otherwise this unit will be on sale on E-bay as is
to the highest bidder.

Hi...

The thread's been long enough and old enough that I've forgotten
most of what's gone before, but you have tried running it with a
real load, haven't you? Possible that the controller is smart enough
to realize that there's no current being drawn, so why waste fuel, just
provide enough so that it can sense current draw and step it up when
there is a worthwhile load? Dunno, just thinking. Try a couple of
100 watt bulbs, or a portable electric heater or something just for
the heck of it.

And you'll probably punch me in the nose for it, but you don't happen
to have a "range doubler" meter, do you?

Take care.

Ken

 

[Fred McKenzie]

I removed the brushes and seated them properly, it seems they were
already seated OK. Changed the wires to the brushes opposite to how
they were hooked up, got 0 voltage. Reversed them and I get 65vac @
the 120 outlets and 120vac @ the 240 outlet. There's nobody local, but
I'm gonna try the closest to me, about 50 miles away that supposedly
works on generators. Otherwise this unit will be on sale on E-bay as is
to the highest bidder.

Ellombris-

It can be frustrating. If the System Control Board (where voltage is
adjusted) happens to be bad, they cost around $200 to replace. Unless
you had one to try, you can't be sure the old one is bad!

You might measure the DC voltage across the brushes when it is putting
out 65 VAC, to get an idea how it is performing. You might also
reconnect the brushes to an external DC power supply, and see what
voltage it takes to get the proper output.

Of course this information would only be of value if you knew what to
compare it with, but you could verify that the alternator is capable of
putting out full voltage.

Applying a load and measuring voltage change would give you an idea of
regulation. If it falls from half value to zero, the problem is worse
than if it only drops ten percent!

Fred