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Generator again

Tue Nov 06, 2012 10:23 pm

I ran through the trouble guide and the generator is the issue. Took it apart and found a busted wire. Winding insulation is in bad shape. Tried to patch her up but It looks like the A terminal is shorted. Any options for under $100?

Re: Generator again

Tue Nov 06, 2012 10:31 pm

I took my generators to my local authorized AC Delco Service Centre. They cleaned and repaired them for a very reasonable charge. I would suggest that you look at that option or at least an olde tyme Generator/Alternator/Starter repair shop.

Re: Generator again

Tue Nov 06, 2012 10:38 pm

Yea, look up you're local automotive electrical shop, or armature shop. I've had several Cub Cadet starter/generators rebuilt for around $75 each.

Re: Generator again

Wed Nov 07, 2012 12:20 pm

mrdibs wrote:I ran through the trouble guide and the generator is the issue. Took it apart and found a busted wire. Winding insulation is in bad shape. Tried to patch her up but It looks like the A terminal is shorted. Any options for under $100?


How is the "A" terminal shorted? Cracked plastic spacer? If so a replacement can be made from parts at Lowes for a few dollars.

Re: Generator again

Wed Nov 07, 2012 1:16 pm

Landreo wrote:
mrdibs wrote:I ran through the trouble guide and the generator is the issue. Took it apart and found a busted wire. Winding insulation is in bad shape. Tried to patch her up but It looks like the A terminal is shorted. Any options for under $100?


How is the "A" terminal shorted? Cracked plastic spacer? If so a replacement can be made from parts at Lowes for a few dollars.


When I short the regulator to test if it's good, the ammeter goes negative. I'm assuming that this means the A terminal is grounded. Both wires leading from A and F internally were frayed and/or broken. I taped them up inside and thought that would eleviate the short, but it did not. Protective tape around the windings is brittle and much of it is just gone, so my thought is that one of the coils is shorted. Or I could be way off.

Re: Generator again

Wed Nov 07, 2012 1:28 pm

Is the ammeter polarity correct? If it's reversed, the generator could be charging while the meter shows discharge.

Re: Generator again

Wed Nov 07, 2012 1:37 pm

To check the fields, Remove them from the genny and lay them on the bench, even the they ohm out good do not ASSUME!!! they are good, Take a battery charger find yourself a old headlamp out of a car or lawnmower hook power to one end of the field and the other to the lamp and ground the other terminal the lamp should light up, Leave it going for a good little while,watch the light,once the fields start to get warm or hot be sure the light stays the same and not dim down. If light does dim down replace the fields. You can wrap them with friction tape like you use on baseball bats or hockey sticks,I get mine from Lowes.

Re: Generator again

Wed Nov 07, 2012 2:31 pm

oronc wrote:To check the fields, Remove them from the genny and lay them on the bench, even the they ohm out good do not ASSUME!!! they are good, Take a battery charger find yourself a old headlamp out of a car or lawnmower hook power to one end of the field and the other to the lamp and ground the other terminal the lamp should light up, Leave it going for a good little while,watch the light,once the fields start to get warm or hot be sure the light stays the same and not dim down. If light does dim down replace the fields. You can wrap them with friction tape like you use on baseball bats or hockey sticks,I get mine from Lowes.


Ok, I think you've inspired me to go a little further before spending my precious project money. For the field wires that extend out of the fields to connect to terminals, should I spray some paint on them or something? They seem to have a coating, but there are bare spots. Also, does the third brush connect to anything? Mine does not.

To answer Fcubman, the meter seems correct. It shows a discharge when I turn on the lights and zero otherwise.

Re: Generator again

Wed Nov 07, 2012 3:44 pm

mrdibs wrote:
Landreo wrote:
mrdibs wrote:I ran through the trouble guide and the generator is the issue. Took it apart and found a busted wire. Winding insulation is in bad shape. Tried to patch her up but It looks like the A terminal is shorted. Any options for under $100?


How is the "A" terminal shorted? Cracked plastic spacer? If so a replacement can be made from parts at Lowes for a few dollars.


When I short the regulator to test if it's good, the ammeter goes negative. I'm assuming that this means the A terminal is grounded. Both wires leading from A and F internally were frayed and/or broken. I taped them up inside and thought that would eleviate the short, but it did not. Protective tape around the windings is brittle and much of it is just gone, so my thought is that one of the coils is shorted. Or I could be way off.


I am not sure what you mean by "short the regulator" . You should ground the field terminal of the gen and if it charges then the gen is working at least somewhat.

Where do your field wires connect? One goes to the "F" terminal sticking out the side of the gen and the other goes to the 3rd brush.

Re: Generator again

Thu Nov 08, 2012 9:46 am

One of the field coils is shorted against the chassis. No doubt now. It's actually loose. Any tips on getting that big screw out so I can replace or fix it?

Re: Generator again

Thu Nov 08, 2012 10:04 am

In the old days, big screwdriver tips were used in bit braces for those. The screw is very short. The rebuild shop has tools for the job. Some big screwdrivers have square shafts to permit using a wrench on them, but to prevent damage to the screw, three or four hands are needed to hold everything properly.

https://www.google.com/search?q=Bit+bra ... 66&bih=624

Re: Generator again

Thu Nov 08, 2012 10:10 am

Field coils any tips on getting that big screw out so I can replace or fix it?
Large impact screw driver. Lesser optimal choice is to take a small punch and hammer to break loose the screw.

Winding insulation is in bad shape.
I think your best bet is to have one of the shops that specializes in starter and generator repair take a look at the generator.

Any options for under $100?
Alternator conversion.

Re: Generator again

Thu Nov 08, 2012 11:57 am

mrdibs wrote:
oronc wrote:To check the fields, Remove them from the genny and lay them on the bench, even the they ohm out good do not ASSUME!!! they are good, Take a battery charger find yourself a old headlamp out of a car or lawnmower hook power to one end of the field and the other to the lamp and ground the other terminal the lamp should light up, Leave it going for a good little while,watch the light,once the fields start to get warm or hot be sure the light stays the same and not dim down. If light does dim down replace the fields. You can wrap them with friction tape like you use on baseball bats or hockey sticks,I get mine from Lowes.


Ok, I think you've inspired me to go a little further before spending my precious project money. For the field wires that extend out of the fields to connect to terminals, should I spray some paint on them or something? They seem to have a coating, but there are bare spots. Also, does the third brush connect to anything? Mine does not.

To answer Fcubman, the meter seems correct. It shows a discharge when I turn on the lights and zero otherwise.



NO PAINT, so long as they are not touching the case you are go to go, The third brush holder will have a wire that is grounded to the case that is correct,The tool I use is what ya call a impact driver that has screwdriver bits that goes in the end of it and ya whop that sucker with a hammer, mine is a Craftsman if ya want go to Sears websight to take a look. As far as switching to 12 volt, Not me! cheaper to fix the 6 volt. JUST MY OPINION!!! Don't want to start a fight.

Re: Generator again

Thu Nov 08, 2012 11:58 am

mrdibs wrote:
oronc wrote:To check the fields, Remove them from the genny and lay them on the bench, even the they ohm out good do not ASSUME!!! they are good, Take a battery charger find yourself a old headlamp out of a car or lawnmower hook power to one end of the field and the other to the lamp and ground the other terminal the lamp should light up, Leave it going for a good little while,watch the light,once the fields start to get warm or hot be sure the light stays the same and not dim down. If light does dim down replace the fields. You can wrap them with friction tape like you use on baseball bats or hockey sticks,I get mine from Lowes.


Ok, I think you've inspired me to go a little further before spending my precious project money. For the field wires that extend out of the fields to connect to terminals, should I spray some paint on them or something? They seem to have a coating, but there are bare spots. Also, does the third brush connect to anything? Mine does not.

To answer Fcubman, the meter seems correct. It shows a discharge when I turn on the lights and zero otherwise.



NO PAINT, so long as they are not touching the case you are go to go, The third brush holder will have a wire that is grounded to the case that is correct,The tool I use is what ya call a impact driver that has screwdriver bits that goes in the end of it and ya whop that sucker with a hammer, mine is a Craftsman if ya want go to Sears websight to take a look. As far as switching to 12 volt, Not me! cheaper to fix the 6 volt. JUST MY OPINION!!! Don't want to start a fight.

Re: Generator again

Thu Nov 08, 2012 12:35 pm

Those field coils must be held so that they do not move at all. Ideally, the clearance between them and the rotating armature should be a the absolute minimum and yet they should never touch. The coils are subjected to many pulls and pushes with each rotation of the armature because of the magnetism involved. If you do remove the coil yourself, the back surfaces of the coil assembly and the generator housing must be perfectly clean for the tightest fit. And the screw must be TIGHT.
I suggest just taking it to the shop for repair. It is very easy for the inexperienced to really mess up with these-- don't ask me how I know.
At one time, plenty of aftermarket companies made replacement components for automotive generators and their sales people called on the rebuilders regularly. As far as I know, the present source of such components is old new stock or salvaged used parts.
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