Ammeter, Plus or Minus Charging

Fri Mar 08, 2013 5:37 pm

Guys, I have two Cubs. One a 1950 with a Magneto ignition (Jenny), one with a distributor (Jersey), a 1952 model. Jenny is in working order with a new clutch and she runs great, but the Ammeter is reading on the minus side. I bought her a year ago.. What do I need to look for to get her in the charging mode. Where do I need to place my volt meter leads to see if the generator is working.
Thanks for your help in advance.

Re: Ammeter, Plus or Minus Charging

Fri Mar 08, 2013 6:04 pm

Welcome to the forum. You can check voltage output at the battery terminals. The link below will also help in troubleshooting
http://www.cleancomputes.com/Cub/Mainte ... 0Chart.jpg

Re: Ammeter, Plus or Minus Charging

Fri Mar 08, 2013 7:01 pm

Thanks Bill, Will follow the chart and test. Thanks for the help. Will respond with the result
Wagon

Re: Ammeter, Plus or Minus Charging

Fri Mar 08, 2013 8:28 pm

Wagon19 wrote:Jenny is in working order with a new clutch and she runs great, but the Ammeter is reading on the minus side.


Is this Cub positive ground or negative ground? That does make a difference. The Cubs are positive ground originally, so if someone changed the ground then the ammeter is wired backwards and will show a negative even though it is charging. If your Cub is still positive ground, you may need to polarize the generator. How To Polarize Your Generator.

Re: Ammeter, Plus or Minus Charging

Sat Mar 09, 2013 7:59 pm

Rudi, thanks. I did change the battery cables, and the ammeter started reading on the positive side at about 12 amps.
I had no idea someone had changed it over to a negative ground. The started drags, but will start once she turns over twice. It has a new battery with a full charge. Does it sound like starter problem, or a wiring or connection problem

Re: Ammeter, Plus or Minus Charging

Sat Mar 09, 2013 10:20 pm

Check connections for cleanliness. Use a volt ohm meter to check continuity and resistance. Use heavy jumper cable to jump from battery terminal to starter terminal. If it starts better it's the wire, if not it's the starter.

Re: Ammeter, Plus or Minus Charging

Sun Mar 10, 2013 7:07 am

Check voltage across the battery, while attempting to start, then check it at the starter under the same condition. If there is a big difference, it's a cable problem, if not, it's a starter problem. It could be the switch on the starter.

Re: Ammeter, Plus or Minus Charging

Sun Mar 10, 2013 2:03 pm

I agree with Gary and Dan. I don't think it is so much the starter as the connections. Start at the battery and ensure the terminals are clean and bright as well as the cable terminal ends. Check for cracks in the insulation and any corrosion. Most likely though will be the saddle switch.... don't ask why I am leaning toward the switch. They can corrode easily especially if it is one of the cheaper after market ones. Remove the saddle switch and clean it up good so everything is bright and clean. You should notice a lot better movement when you pull the starter rod.

Keep us posted.

Re: Ammeter, Plus or Minus Charging

Sun Mar 10, 2013 6:29 pm

Guys, just put new ends on an old battery cable and fastened one end onto the starter post and a new end on the battery post. Jenny started much better. Next I will will check the saddle switch and clean it up. I remember a couple of years ago, that was the main problem with the Ferguson TO 20.
I appreciate all of your help and suggestions.

Re: Ammeter, Plus or Minus Charging

Sun Mar 10, 2013 6:40 pm

Remember that the new ends are a temp fix. They love to harbour corrosion. Use tinned wire with crimped ends, not the ones that bolt on. Otherwise go for a new cable. Just my opinion.

Re: Ammeter, Plus or Minus Charging

Sun Mar 10, 2013 8:50 pm

Wagon:

Check this out : How To Build A Replacement Battery Cable. It pays for itself in a very short time :!:

Re: Ammeter, Plus or Minus Charging

Mon Mar 11, 2013 9:09 am

I read the link. Beats the heck out of paying $98.00 for a new cable. It will take a few days for me to get to this, maybe next weekend. Will let you know how it all turns out
Wagon