1985/6 312-8 Battery charging system

[Yitzchok 4]

Hi, when its off and i test the battery its like 13v when its running and i test the voltage at the battery the numbers are jumping way up (up and down) (the meter on it is broken so i was using a multimeter but it is a cheap one so idk) it's going all the way up to like 45v what should i do?

[ineedanother 2,294]

Are you just randomly testing something or is there an issue or problem that you are trying to diagnose?

[gwest_ca-(File Mod) 12,225]

Some digital multimeters will pick up interference with the engine running so not any help with diagnosis.

Most older analog meters with a needle do much better. Perhaps you could borrow one or replace the original with an automotive style the same size. They are not that expensive.

[Achto 31,776]

8 hours ago, Yitzchok said:

i was using a multimeter but it is a cheap one so idk)

 

I you question your meter, test your meter at a known source. This should ALWAYS be practiced when testing AC voltage in your home.

 

Test you car battery for example, should be around 12.5v with the engine off and around 14v with it running. A bad battery in the meter can cause your readings to be off.

[953 nut 65,935]

7 hours ago, gwest_ca said:

digital multimeters will pick up interference with the engine running so not any help with diagnosis.

Gary has the problem diagnosed properly.  If you place the multimeter on the seat of the tractor it will be far enough from the engine to give a better reading.