Phil,
Thanks for the post
" I removed the pump from the trunk and took the cover with the four screws off the back. Inside there is a circuit board with wires attached. I lifted this board away from the chamber that it was mounted in. Underneath I found that the board was connected to two long, small width spade connectors. I cleaned these connectors and bent them slightly for better contact. Also on the board is a small relay. I cleaned all the contacts on this. I then put it all back together. It all works perfectly now."

I have removed the pump, but I can't find the circuit board you refer to. Did you take the pump apart? Also, for what its worth, the last time I plugged and unplugged this pump, I blew my #13 fuse.

__________________
1989 300E
103,500 miles

1982 300SD
Sold but not forgotten