Case 580SK Charging Question

Hello guys. I have a Case 580SK with an odd charging issue. The alt light does not come on, the tach does not work and it does not charge unless I briefly jump the terminal on the alternator to positive. I can immediately remove the jumper and it charges, the tach works, etc. until I key-off again.

I assume there's a relay?

Thanks in advance for any thoughts and insight; much appreciated!

Case 580SK Charging Question