> From:    David Clarkson <dvdclarksn@AOL.COM>
> Date:    Tue, 3 Apr 2007 15:16:57 -0400
>
> I also have to figure the electrical connections of 1 wire on the
> [Sanden] 510 vs. 2 wires for the clutch on the wiring harness that's
> in the vehicle.

Most likely, the one wire on the Sanden 510 is the hot wire for the
clutch, and it grounds through the compressor mounting bolts.  The 2
wires on the harness are _probably_ a hot wire and a separate ground
wire.  The other possibility is that one of the wires in the harness
is the hot wire for the clutch and the other goes to a pressure switch
that was installed on the original compressor.

The wiring diagram in the Bentley should tell you what's up on the
vehicle harness side.  If there is a ground wire, it can't hurt to
connect it to the body of the new compressor or under one of the
mounting bolts (as long as it doesn't tend to make the bolt loosen
up).

I don't know about the relative performance of the 5 vs 7 piston
compressors or their suitability for R-134a.

Matt Roberds