Took the starter off the 70 gs (350) this week. Shop installed new solenoid, brushes and bushings. When I took it off there was the wire from the battery and a small one on the S or switch terminal. Another wire is hide in black tape around the battery wire. What does the R terminal provide? I know I have been swamped with the house move and my mind is overloaded but I felt sure there was nothing on this post when I removed it.
R terminal goes to the coil to provide a hotter spark during cranking.Not needed with HEI or points conversions.
