Generator not charging?

P

pcpat

Junior Member
I'm having a strange charging issue; I looked at the Amp meter in the cab and it is not showing a charge (0 Amps). I took it for a short drive and still the Amp meter shows zero - when I turn on the lights or blow the horn it shows a discharge.
I put my volt meter on the generator side of the cut out and it shows 7 volts from the generator... Then I look at the amp meter inside and it shows its now charging (about 5 - 7 amps at Idle).
Shut off and restart the engine and the amp meter shows no charge until I put the voltmeter on the generator and then it shows its charging?
When driving the amp meter will eventually go back to no longer charging (0 amps again)
I haven't had a chance to look into the issue yet. I was going to try and swap out the cut out with another one I have on hand. I wanted some thoughts if anyone has any other ideas?

Thank you,

Pat
 
It could be any number of things. An intermittent ground, worn brushes, a sticky cutout, loose connection etc. Start be checking all these things. If its any help, I have refurbished and tested original Ford cutouts available.
 
Easy cutout test: Put a jumper wire around the cutout, one end on the generator terminal and the other on the output terminal of your cutout. No need to remove the cutout. Now run the engine and check for a charge. Don't leave the jumper wires connected after you shut off the engine, or the battery will drain through the generator.
 
If it has an original type cut out relay then it may be having an issue. It may need cleaning of the points or it may have core wire or connection problems. They are adjusted to come on line just above battery nominal voltage. If it has a diode inside a cut out can then the diode may be going south. Insure the connections to the cut out relay or diode are clean and secure.

The generator generates the voltage off of residual magnetism in the pole shoes to bring the unit on line. This is the reason for flashing the field to magnetize the pole shoes in proper polarity. When used often enough, the magnetic gauss remains relatively strong in the pole shoes. If they are replaced or set dormant for a very long time then they need to be repolarized/remagnetized. The generator isn't voltage regulated until the battery comes on line so it should easily generate the voltage needed to close the points on the cut out relay. If brushes are worn or connections are spotty then it may have an issue.
 
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One of my Cut-outs is a voltage regulator. It only shows a charge for a few seconds when the car is first started after having sat for a long period of time. Otherwise no charging indicated. It will show a discharge when the lights are turned on. Perhaps your cut-out is the same?
 
I had a similar charging problem with my generator. The issue for me was poor ground at the generator mount point. Cleaning this area up took care of it.
 
Sorry for the delay in getting back, It looks like the bad ground may be the culprit (or it could be the old brittle wires). But I only had a short time to work on it the other night. It looks to be charging but I didn't have a chance to take it out for a run yet. That will have to be on Sunday since the weather on Saturday looks like it is gonna be kinda rough. Thanks for the advice and suggestions
 
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