Alternator/reg. question

[Bradley Wayne]

I have a JD 3020,1969 that has had the alt. lite on for over a year now. The batteries are two 6volts in series. one measures 6.4v and the other measures 5.6v . Is there any way to test the alt/reg with a multimeter? and what would cause the alt. lite to stay on if the batteries have been charging the last year? At present the engine is NOT turning over due to low voltage???

Any and all input is appricieated. Thanks. Brad - bwsnjake@yahoo.com

 

[jenkinsph]

If the batteries are in series with one having a low voltage I would check this out first, likely you have a bad cell in the battery. Current has to pass through both batteries to be able to start the tractor so if one of the batteries is failing it will limit the ability of both batteries.

With both batteries charged properly you should have a minimum combined voltage of 12.6 and likely will read higher. With engine running at a fast idle you should have 13 to 14.5 volts (just guessing).