alternator update

Ellis Kinney · Sep 29, 2020

A couple of days ago I posted about my alternator not charging. I took it in for a free analysis and it is charging fine. Fellow looked at the pulley and said my belt was glazed. I know the belt was tight enough so I wire wheeled the pulleys and put belt dressing on the belt. As soon as I get the radiator back I will know it it is charging again. Ellis

c.oawright · Sep 29, 2020

Is this alternator a 10 SI Delco. If it is check the post marked 2 and see if has plus 12 volts on it. That terminal is the line that excites the field and starts the alternator.
Some have the number two post going straight to the battery plus through the ignition switch and some have it connected to plus battery with an oil pressure switch.
Put a volt meter across the battery terminals and measure the voltage. Start the tractor and see if the voltage goes up to 13.8 to 14 Volts. If not, take a jumper wire and momentarily apply 12 volt battery plus terminal to number two connector. If the voltage rises then you excited the alternator. Then look where the wire going to terminal 2 is going.

Steve@Advance · Sep 29, 2020

If the belt has ever been run loose, or if it's too narrow for the alternator OR the crank pulley, it will run against the bottom and not grip the sides as it should.

A common problem, the old engines originally came with a wide belt. Modern alternators have a narrow pulley. You can buy a wide pulley for the alternator, which will let you run a belt that better fits the crank and water pump.

If either pulley is shiny in the bottom, it's running too low.

A good way to check the belt grip, push against the alternator fan with your thumb. It should be near impossible to slip or might even turn the engine without slipping.

alternator update

Ellis Kinney

Well-known Member

c.oawright

Member

Steve@Advance

Well-known Member

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