I installed an M3 Starter in my 74 Tii. My original starter still worked and was drawing about 30 amps but still seemed a little weak. With the timing properly set, during start up, the engine would slightly try to kick back just before the engine would start. Rather than rebuild the original, I chose to upgrade. I finished the installation last night. The difference is amazing. Engine starts quicker and starter turns motor over with authority.
I did have one wiring issue that I have not figured out. I was unsure which of the small clip on wires went on the top terminal. I installed it the way I thought it should go. The engine would start but would die immediately after the starter quit. I could tell the ignition was loosing power when the starter quit because the red light on my Crane 3000 ignition would go out when the starter quit. I swapped the top and bottom wires and the starter motor would turn but not engage. The starter might have been turning backwards but since the battery wire and the ground wire were not changed , I am unsure. But it did not work that way so I swapped the wires back. Now the larger of two small wires was on the bottom terminal of the solenoid (50). The large power cable from the battery was on the large terminal 30 . This starter had a second terminal 30(not 15) on the top. The single black wire was connected here. I think this is the wire that is supposed to give full voltage to the coil and points during start up bypassing the ballast. When I disconnected this wire, everything worked ! After starting the engine, if this wire was connected, the engine immediately died. It is like it shorted out power to the ignition. My electronic ignition gets its power from the coil, but I can’t figure out why connecting this wire would short out ignition. Any body know what’s going on? Well anyway If I just leave this wire disconnected, the starter works great! Should have done this years ago.