My recent experience might help. Supercharger quit engaging and of course I went right to the forum. Had to be an I/C pump. Bought Johnson pump, wired it up and no supercharger. Next...had to be the IAT sensor. Ordered one off eBay and then I came across two things on the forum; one guy mentioned it was his RCM, and another had a complete wiring diagram for the supercharger pulley. I took one look at it and low and behold everything starts in the RCM fuse #2. I got home, pulled the fuse with the key on, and my cooling fan turned on full speed, and the supercharger pulley started rapidly engaging and disengaging right in front of me. I had a spare RCM I ordered off eBay a couple of years ago. Changed it out and off I went. No problem.

I should have ran it down before buying the pump..BUT good things came out of the endeavor. I have the 62mm pulley and probably needed the Johnson pump and more volume, I gapped the supercharger pulley, and wired the pump off the ignition in the process. Before buying the pump CHECK it. My old man would smack me up side the head if he was alive and knew I didn't check it before replacing it. I actually heard him in my head saying "check it first Mick." But nooooo.......right to a $149.00 Johnson pump.

All good...and without this forum I would probably have it in the shop spending lots more $$$$.