Welcome to JA!
Can you tell me is this is alt single wire alternator or the 3 wire alt.
do you know the build date.
if not the vin# XXXXX work
On the 3 wire alternator
the alternator is grounded threw the body of the alternator,
the 2 service wires run to the gage on the dash to complete the circuit
and the main wire runs to the starter solenoid,
Most common is the alternator loosing the ground
and then from there you can see if the circuit is completing at the gage.
There is a link with a service and shop manual for your tractor
Let me know if i can help more!
Here is the list of alternators for the 210c depending on the alternator depends on the wire numbers
do you see anything close?
Alternator,assembly. 12 volt, 90 amp, less pulley. For model 210C, (C, D, E), TY2485 and Bosch 0-120-484-011. (Part No: TP-TY6750),(ttb 11989), 6654r21, ggb88632. a54671121 p5445672 - ground
Is this your alternator