On a 3800sc swap... Using the stock 88 Fiero oil pressure switch, (3 wires) and "hot wiring" the fuel pump using Ryan's instructions at gmtuners.com. Since you are removing the backup fuel pump power capabilites of the oil pressure switch and the new fuel pump will be powered by the new relay,and power feed, you are told to cut the tan/white wire coming off the oil pressure sender. I know the tan/blackwire goes to the c203 and then to the gauge to give the oil pressure reading, but what about the orange/black? Does it still need switched power?

There was a diagram in the haynes manual and it appeared the orange/black was only providing power to the fuel pump, and not needed, however, i would think that the orange/black needs power to make the pressure sensor actually work. so.. what is correct?

Anyone?

The center pin supplies the gauge input. The two side pins are used for the secondary fuel pump circuit but its really not needed. I carried a spare relay in case it was needed but recently wired in a duplex relay as part of hotwire run to the fuel pump.

------------------
" THE BLACK PARALYZER" -87GT 3800SC Series III engine, 3.4" Pulley, N* TB, LS1 MAF, Flotech Exhaust Autolite 104's Custom CAI 4T65eHD w. custom axles, HP Tuners VCM Suite.
"THE COLUSSUS"
87GT - ALL OUT 3.4L Turbocharged engine, Garrett Hybrid Turbo, MSD ign., modified TH125H
" ON THE LOOSE WITHOUT THE JUICE "

The only one you NEED is the center pin to the oil gauge. The two outside pins are not needed unless you wish to wire in the fuel pump backup feature (I never do).

Dennis beat me to it !

[This message has been edited by Mike Gonzalez (edited 08-31-2010).]