Originally Posted by Lambrettaman

To close this one out. After fun-filled trip around the internet searching for information and images on the R4 compressor, I'm fairly certain it doesn't matter which lead goes to which terminal. I can't point to any hard evidence for it, mind you, but then again, if there is no evidence one way or another, I figured it was a safe guess that it doesn't matter.

I wired mine up with the green wire on the bottom and the brown on top. The AC works fine now (at least as fine as a W123 stock system will work at 105^F and 18% humidity.