How to check my generator

D's31

D's31

Member
Hi
I have a 1931 Tudor, how do I test the generator to make sure it works? I looked online and they show some that do not look anything like mine. My generator has the cutout at the top and only two wire hook up to it on the right side of it one I'm guessing for the lights and the other one I'm guessing goes to the terminal box. On the left side there is no wire to that screw. The cut out hasn't had the top on side I've owned it, does it need the top on to work? Is the little spring supposed to go up and down? Any help? What is the cutout for?
 
Since your generator doesn't look anything like the online pictures how about posting a picture so we know what you are starting with?

Charlie Stephens
 
Find all older posts from Tom Wesenberg or send him a PM, he is the fordbarn guru of generator troubleshooting!
 
This is what it looks like
 

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You are missing the cover that goes over the mechanics of the cutout. It appears to be connected correctly. For proper operation, the relay should be in the position that it is now with everything off. There should be no connection between the input where the front of the cut out connects to the terminal out of the generator and the output of the cutout where the two wires attach. (there should be three wires there, one for headlights, one for the horn and one to the terminal box.) When you start the vehicle, and the generator starts working, the relay should move down and there is a connection between the generator output at the front of the cutout to the wires at the other end. If you plan on messing around with the points on the relay, remove one of the battery connections before touching anything inside as will get a lot of sparks. You need to get a new cut out that has a cover.
 
Turn on the lights. Does the ammeter show discharge ? It should.

When running at a fast idle does the ammeter show a charge ? If so, how much ?
Turn on the lights, at fast idle, how much charge is showing ?

If there is no charge, then try polarizing the generator by jumping across the 2 cut-out terminals for a nano-second.

The cut-out is basically just a switch to disconnect the battery when the engine isn't running. Many non- model A folks mistake it as a regulator. The charge amount is controlled by the setting of a movable brush under the generator band.

A quick basic check of the generator is to loosen the fan belt and then supply power to the generator and see if it motors. If it does, its probably good.
 
D's31 said:
This is what it looks like
Click to expand...

Thanks for the pictures. Without them it could have been an alternator or a Chevrolet generator that was adapted. It sounds like you have enough information to solve your problem. As an aside you can add multiple pictures to one post, go to the test forum and practice.

Charlie Stephens
 
Patrick L. said:
Turn on the lights. Does the ammeter show discharge ? It should.

When running at a fast idle does the ammeter show a charge ? If so, how much ?
Turn on the lights, at fast idle, how much charge is showing ?

If there is no charge, then try polarizing the generator by jumping across the 2 cut-out terminals for a nano-second.

The cut-out is basically just a switch to disconnect the battery when the engine isn't running. Many non- model A folks mistake it as a regulator. The charge amount is controlled by the setting of a movable brush under the generator band.

A quick basic check of the generator is to loosen the fan belt and then supply power to the generator and see if it motors. If it does, its probably good.[/QUOTE

When I turn the lights on the ammeter shows a discharge of 10 when running at fast idle it shows no charge and when turning the lights on on fast idle the ammeter shows discharge of 10. Never does it show any charge
Click to expand...
 
Your generator has a starter band on it, but that's OK.
Your generator is correct for 1929 through early 1930 Model A's, but will work for all years.
That cutout is a cheap piece of junk repro. Bert's sell restored original cutouts, or you could use a quality diode cutout.

Right now I'd remove the belt and jump across the two cutout terminals with a short wire. If the generator doesn't spin in the normal direction of rotation, then it needs to be rebuilt. If it spins, then put the belt back on and start then engine, then jump across the two cutout terminals with a clip lead and rev the engine a little and see if it charges.

Let us know what you find.
 
isnt it annoying how no one ever gives a straight answer in this today we live in. well im different. get out your voltage meter/ multi meter set it to volts. at idle if your generator is working as good as mine it will read 12v at idle. when the engine is reved up it will read 25v. I am converting my car to 12v. i have isolated my ignition sytem with a 6v ballast resistor. but have done nothing to the generator. that i have to assume is a original ford 6v generator. someone will probably correct me if my numbers are wrong.
 
If you're reading 25 volts when you rev it up, then your charging circuit has an open or the battery has too much resistance.
 
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D's31;1215002 [I said:
When I turn the lights on the ammeter shows a discharge of 10 when running at fast idle it shows no charge and when turning the lights on on fast idle the ammeter shows discharge of 10. Never does it show any charge[/I]
Click to expand...

Let's make this simple. I'm sure we have the expertise right here to solve your problem.

Look at the photo. When the motor is running, the plate with the points on it should automatically be pulled down so the points make contact. (See the white arrow) This will send the generated charge through to the ammeter which will then show a charge. If there is no positive reading on the ammeter then either there is no current being generated or the cutout is not pulling the points together and is defective.

Clean the points with sandpaper to make sure they will have a good contact. Then, with the motor running, have somebody watch the ammeter while you push the points together with a screwdriver. If the ammeter then shows a charge, the generator is OK and the cutout is bad. If it shows no charge then the generator is not working.

Like I said, we have enough experts here to solve the problem, so if I am wrong they will chime in and tell me real quick! :)
 

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Good information just given by CHL.

Also look at the bottom connection where the heavy wire coil should be soldered to the terminal. It looks like the wire has overheated and melted the solder away. With a good cleaning of the contacts and resoldering that wire, you might actually make this work again, but I would still ditch it and buy a better quality one. I've seen a lot of these cheap ones burned beyond use.

Either a diode cutout or good original is what I'd use. I like the original style, and Bert's sells good restored original cutouts. 800-321-1931
 
Tom Wesenberg said:
If you're reading 25 volts when you rev it up, then your charging circuit has an open or the battery has too much resistance.
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then what should it read? seeing you know what it should read you should probably tell the guy who asked how to check his generator. thats why i dont ask questions here. its more effective to hit your self with a hammer and hope the answer comes to you.
 
Since the generator is unregulated it should read slightly more than battery voltage when it's charging. If you battery reads 6.3 volts with the engine off, then it should read about 6.7 with the generator charging.

If the battery isn't connected, then the voltage can go up to 40 volts and cook the bulbs and generator. So, if the cutout goes bad you should just jump across the two cutout terminals while the engine is running, or you can ground the output post on the generator, so the output stays at 0 volts. Either way will get you safely home.
 
mike657894 said:
then what should it read? seeing you know what it should read you should probably tell the guy who asked how to check his generator. thats why i dont ask questions here. its more effective to hit your self with a hammer and hope the answer comes to you.
Click to expand...

Tom did not deserve that, he was just trying to help..
Please use a dead blow if you must
 
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