Cutout problem, I think!

Jump across the cutout terminals with a short wire. Do you see a small spark? This will polarize the generator. Now start the engine and run at fast idle. Measure the voltage at the generator output stud. If it's 0 volts, then remove the cutout and measure it again.

Sometimes people use too long a screw on the cutout and short the windings, or they may have left off an insulating washer and grounded the generator output.

So, if you have polarized the generator, removed the cutout, and still show 0 volts at the output stud, then the generator needs to come apart and be checked.
 
Thanks Tom. I did jump the cutout. With the engine running, I then tried to get my test light to light on the generator side of the cutout and did not get any light. I did not take the cutout off and try it. But yesterday I finally got fed up trying stuff and one of our guys from our Model A club that works on generators came by so I gave them to him to fix.

Notice I said "them" because my coupe's generator had been acting up over the last couple of months so when I tried to start the coupe a couple of days ago, the battery was down. When I jumped the battery, the coupe's generator would not gen either. So that is when I gave up and gave the fellow both of them to fix.

Thanks again to you Tom for the ideas and to everyone else that gave me ideas. When I get the "good" news back from the repair guy, I will post what problems he found.
 
Hey Fred, I have an alternator but am having almost identical issues. I have not tried all the tricks listed here to diagnose but am hoping you can save me some time and headache :). Did you find the problem?
 
Sounds like the field coils stopped working. Take the gen apart and look to see if the small wire that connects the two field windings is intact. If not the field won't work. Just solder it back together and check continuity with an ohmmeter or battery charger. Make sure that wire gets taped so it doesn't short against the through bolt.
 
30FordA50 said:
Hey Fred, I have an alternator but am having almost identical issues. I have not tried all the tricks listed here to diagnose but am hoping you can save me some time and headache :). Did you find the problem?
Click to expand...

I took the generator to a guy to have it fixed and he found one of the screws that hold the cutout on, was to long, and it went into the windings.
 
Glad you found it Fred. I believe Tom W has mentioned this possibility in the past.
Its the simple things that get us.
 
Will N said:
Depending on what caused your fuse to blow and how fast your generator was turning when it blew, the generator might be fried. The battery acts as a voltage regulator in the system. If you were winding it out when the fuse blew, the battery was taken out of the circuit, and the voltage coming out of the generator could have run way up to 20+ volts which could burn out the windings. Had this happen to me. Tom Wessenberg recommended to test the field coils by disconnecting the wiring from the generator body and brush, hook up a battery charger to the two wires, and check the amperage draw. Anything more than 4 amps means your field coil is fried.
Click to expand...


If that means to disconnect the grounded brush, I think it would be easier and quicker to just put a non-conducting insulator between the brush and the commutator or just pull the brush away from the commutator with a string.
 
You'll need to disconnect the ground side of the field windings to check the fields for shorts to the case. Ant that's what just happened with the cutout mounting screws that were too long. I've found that good fields for the common long style generator will show 4 to 5 amps when connected to a 6 volt battery charger.

The powerhouse have much more wire in the 6 field coils and only draws about 1 1/2 amps for the 5 brush and about 2 amps for the 3 brush powerhouse.
 
You must log in or register to reply here.
Back
Top