Bad Generator...

Sat Feb 08, 2014 7:18 pm

my cub is a 55 with original 6 volt positive ground setup. I just got through replacing the rat's nest of wiring that was there when I got it, and the ammeter shows discharge when running. I've gone through the troubleshooting chart that i've seen referenced here before, and i replaced the old regulator just for good measure, but it seems the generator is in fact the culprit. what are my options? I haven't seen any how-to on rebuilding a generator, is it something that an amateur should attempt?

Re: Bad Generator...

Sat Feb 08, 2014 8:08 pm

Check the voltage at the battery with the engine off then check the battery voltage with the engine running, was it more when running?

Not sure on the cub but on other 12v amp gauges I have seen in the past if you have the wires reversed at the gauge it reads backwards, meaning it will show discharge when its really charging.

voltage goes up when the engine running swap wires at the gauge?

Re: Bad Generator...

Sat Feb 08, 2014 8:14 pm

have you polarized it???????????????????

Re: Bad Generator...

Sat Feb 08, 2014 8:21 pm

I thought about that, but I think it's hooked up correctly. when i turn on the ignition switch (before the engine is turning) the ammeter drops like 1/4 inch to the left, and it stays about the same while the engine is running. I can't test it with the lights, since the bulbs are dead.. I'll double check with the volt meter though. thanks!

Mike in Louisiana wrote:have you polarized it???????????????????


yes, I jumped the batt terminal to the gen terminal at the regulator and it gave one heck of a spark! that's all there is to it right?

Re: Bad Generator...

Sat Feb 08, 2014 8:46 pm

Does the voltage regulator have a good ground? Run a jumper wire to test it.

Re: Bad Generator...

Sat Feb 08, 2014 8:49 pm

Eoghan wrote: I haven't seen any how-to on rebuilding a generator, is it something that an amateur should attempt?
The generator is not that hard to repair. But since you asked the question, my suggestion is to take the generator and regulator to a repair shop.

what are my options?
Well. Not knowing the cost of the generator repair and other repairs - - - I would have initially suggested a conversion to a 12 volt single wire alternator. - - - Much cheaper and more reliable.

Re: Bad Generator...

Sat Feb 08, 2014 11:14 pm

I cleaned up the ground when I replaced the regulator, and I tested it and it's good so that's not the prob.

despite my inexperience, I feel like i have very little to lose, so i'm going to crack open the generator and see what i'm working with. I did some reading and i think i have a basic understanding of the components and how they're supposed to work.

Speaking of which, this site as well as Rudy's manual site are such an amazing resource, I can't thank you guys enough for all the time you've put into it. I'm pretty new to working with cubs (and frankly engines in general), but with the forum search I can almost always find answers to my questions without even having to ask! Thanks to you guys these awesome little tractors are going to be around for a long time to come.

Re: Bad Generator...

Sun Feb 09, 2014 7:04 am

Just read through this:

http://www.cleancomputes.com/Cub/Blue%2 ... trical.htm

and feeling much more confident.

Re: Bad Generator...

Sun Feb 09, 2014 8:13 am

I just had my generator rebuilt. They charged $125

Re: Bad Generator...

Sun Feb 09, 2014 8:34 am

torchred89 wrote:I just had my generator rebuilt. They charged $125


Had one rebuilt, for a relative,about 2 years ago. Same price! Makes the 12 volt conversion, look good! New regulator, at that time, need replacing, again. (I suggested 12V, he wanted "original". )
Ed

Re: Bad Generator...

Sun Feb 09, 2014 8:53 am

problem solved!

The fault was with the regulator. The cutout must have been a little sticky because i had to rev the engine up to full rpms before it kicked in, but then when i throttled down it kept charging fine. The needle on the ammeter is very bouncy when charging, is that normal? I assume it's just the points of the relay opening and closing inside the regulator? The volt meter reads between 12 and 18 volts when running. I wish i had an analog tester, there's a lot of noise going on and the digital can't handle it.

I also see now what i did wrong in my diagnosis: when I bypassed the original regulator the ground was probably bad. then I shined it up when i put on the new regulator, and i never did the bypass test again.. so when it still didn't charge i assumed it was the generator. Next time I'll follow directions better!

I guess now i can put off rebuilding the generator, but I think i might actually open up the old regulator and clean it up since it's a much nicer old delco model compared to the new TSC chinese special I just put on. as for the 12 volt conversion, i have no ideological objections to changing from "original" but my wallet complains when i spend money that i don't need to. the gen rebuild kits i've seen on ebay are less than 20 bucks, and i think you can even get new field coils pretty cheap if they're dinged up. when it's damaged beyond a simple repair or i get tired of the hard cold starting, then I'll think about switching.

Re: Bad Generator...

Sun Feb 09, 2014 8:55 am

Brushes, bushing, and bearing for generators are available from auto parts stores. Cost of common repair parts, not very much.