Tascam 22-2 X-3 Tension arm on off relay switch
This is the small relays that are used on the tension arm to activate the tape ended stop function and I guess activate the Capstan.
This was a spare.
Its always a good idea to let the capstan motor stop when not in use, I see many times peopel with tape in and unit running but not doing anything, taking the time to lower the tap so it switches off will save you pounds on a new motor.