Cutout problem, I think!

Fred K-OR

Fred K-OR

Well-known member
The wife and I went out for a short drive today in the 1929 Huckster. We got out of our driveway, cruised down a short incline, about 300 feet and at the bottom, the old rig died dead. It would turn over but had no horn, light etc. and would not restart. Got out and found the fuse blown.

Put in a new fuse, it did not blow and the rig started like it should. Started driving and noticed the amp meter was not charging at all, just showed a little discharge. Put on the brakes, and it showed more discharge. Continued our trip and make it home after about 15 miles.

Question is what happened? I did not find any loose wires, everything seemed to be the way it should be. The rig ran the way it should for 15 miles except the generator never started generating again. So I am assuming that maybe the cutout stopped working. Am I on the right track? If it is bad, how do I check it out? Need some help from the experts. I have about 2000 miles on the rig since the engine and generator were rebuilt. Thanks
 
May be internal to the generator. You may have caught that small "response time" after the generator shorted, but before the cutout could respond with an open circuit (which it is wont to do on generator not generating.) Enough to take out your fuse.

You could try checking your generator for direct short (remove cutout and try a VOM between generator outlet and ground.) Then maybe try generator motoring with the pulley off. Then maybe try generator generating?

Or maybe a bench test powered by a washing machine motor.

Joe K
 
Thanks Joe, will give it a try in the A.M. when it is a little cooler around here. About 90 degrees now.
 
Fred, you can check the cutout by running a jumper wire from the front terminal to the back. If it charges when your engine is running at a good rate, the cutout is bad. If it doesn't charge, you've got a generator problem. Don't run your engine if it's not showing a charge without the jumper. You'll burn out the generator.
 
hi fred,been playing with this generator prob for a month.used swap meet here to solve problem.ray Horton is right on track about cutout.start from scratch, clean bat terminals on both ends,jump cutout.check fan belt tention,clean terminals on back of ammeter.pull generator,bench test with batt charger.do a search on this forum.all this info came to me from tom w,&others on forum.one check I've used in the past to check generator if ammeter is questionable,disconnect battery while engine running.if generator is ok engine should continue to run.good luck
 
Well did some work on this situation. Did the following so far:
1. Jumped the cutout like Ray mentioned above. Still not charging when motor running.
2. Replaced the cutout with a brand new cutout purchased from Brattens. Still no charging.
3. Took the generator off rig. Put it on the workbench and hooked up the charger to the generator. It motored like it should.
4. The amp meter seems to work the way it should. It shows a slight discharge when motor is running, more discharge when brakes put on but no charge. Maybe next step would be to check out amp meter. Will do in the A.M.

So where do I go from here? Any other ideas. Help Tom W.! All electrical stuff works like it should, starter turns like it always did, horn works, lights work, etc.
 
i like to put an ext volt meter at the generator to see the real output...
regarding the blown fuse ck your junction box connections, and eyeball the other wiring... i once blew the fuse and it never happened again..
are you running a v-regulator ??
 
tbirdtbird said:
Items 1 and 3 are inconsistent with each other
Click to expand...
. It ain't necessarily so! It's a quick test but some times they motor on the bench but don't charge.
Fred K Or Do you think a short could be causing the problem? Is the ammeter showing any discharge when engine off?
 
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.
 
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...

I like this thought. It is possible to "motor" a generator on the basis of residual magnetism. No field, but enough residual to make it (feebly) move.

Check out the wiring diagram at http://www.webjunk.com/modela/wp-content/uploads/2008/02/wiring-diagramcolor2sm.jpg It makes you realize how simple a device a generator really is - well, when the coils are wound correctly and not one reversed.

Joe K
 
Take thecover off generator, look inside for little blobs of solder thrown off commutator, smell if smoke came out of wires

One of the problems with having a fuse in the wire between the generator and the battery is if the fuse or the holder fails while the engine is running is generator failure due to overvoltage, the stock model A 3 brush generator uses the battery for the voltage regulator.

A fuse holder failure on my maiden voyage caused the car to be towed home, the generator to let out some smoke, toss the solder, the local electric motor shop said that I could do a tempoary repair by resoldering the commutator, so far that tempoary repair has lasted 40+ years, the generator would motor, but not make much output, this repair got me started rebuilding generators and starters
 
1930 coupe said:
Everyone that owns and drives a Model A should own a analog multimeter, and learn the basics of how to use it. It would be good if car clubs would have classes on Basic troubleshooting with a meter. Without a meter you can change parts for weeks and spend hundreds of dollars and still not fix your problem. A person with a meter, that knows how to use it can locate where your problem is in 15 or 30 minutes.
Please do not take this statement wrong, this is NOT A PUT DOWN to anyone, but trying to let people know that life would be easier if they had a meter and get someone to show them how to use it.
Click to expand...
I second that, and a test light.
 
A battery is much like a capacitor and running the generator in open circuit really shouldn't bother the wiring. Light bulbs don't like it much.
Fred, if you don't have an analog voltmeter put a test light on the generator side of the cutout. It should be off. Start engine. Does it come on? If so the generator is self exciting and it has to be pretty much spot on to do so. If not pull the generator.
Is that "Irishman" in K-falls still rebuilding?
 
tbirdtbird said:
Items 1 and 3 are inconsistent with each other

what work did you you do to the car before this problem arose
Click to expand...

johnbuckley said:
. It ain't necessarily so! It's a quick test but some times they motor on the bench but don't charge.
Fred K Or Do you think a short could be causing the problem? Is the ammeter showing any discharge when engine off?
Click to expand...

No the ammeter does not show any discharge when the engine is off.
 
Kurt in NJ said:
Take thecover off generator, look inside for little blobs of solder thrown off commutator, smell if smoke came out of wires

One of the problems with having a fuse in the wire between the generator and the battery is if the fuse or the holder fails while the engine is running is generator failure due to overvoltage, the stock model A 3 brush generator uses the battery for the voltage regulator.

A fuse holder failure on my maiden voyage caused the car to be towed home, the generator to let out some smoke, toss the solder, the local electric motor shop said that I could do a tempoary repair by resoldering the commutator, so far that tempoary repair has lasted 40+ years, the generator would motor, but not make much output, this repair got me started rebuilding generators and starters
Click to expand...

Had the wife smell for smoke or burning in the generator. Found no smell or solder either.
 
Willie Krash said:
A battery is much like a capacitor and running the generator in open circuit really shouldn't bother the wiring. Light bulbs don't like it much.
Fred, if you don't have an analog voltmeter put a test light on the generator side of the cutout. It should be off. Start engine. Does it come on? If so the generator is self exciting and it has to be pretty much spot on to do so. If not pull the generator.
Is that "Irishman" in K-falls still rebuilding?
Click to expand...

Mike, the test light does not come on after starting the engine when I put it on the generator side of the cutout.

I am still looking for an analog voltmeter to do some testing. Will keep things posted.
 
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