3800 swap harnesses (Page 10/20) Matthew_Fiero MAY 21, 11:26 AM quote Originally posted by FIEROFLYER: C203 pin B this is power from the furl pump fuse to the fuel pump relay and also a good spot to tap off +12 v battery power for the OBD II DLC connector. I also use heavier gauge wire salvaged from the Fiero engine harness for fuel pump wiring. C203 pin L this is power from the fuel pump relay to the fuel pump and also is a larger gauge wire than the one used in the 3800SC cars I am a little confused on these two.. FIEROFLYER MAY 21, 07:37 PM The fuel pump wiring for the 97 to 2000 models uses two relays one is the fuel pump relay and the other the fuel pump speed control relay. Basically the fuel pump relay switches the +12 volts coming from C203 pin B to the fuel pump through C203 pin L. The speed control relay switches in and out the fuel pump dropping resistor so the +12 volts either goes through the resistor or bypasses the resistor giving the pump full power. If you do not want to use the resistor just do not wire it in, what I do then is run the wiring as if the resistor is used then short the wires together that would have fed the resistor giving the pump full power all the time. the only draw back is the pump is a little noisier during light driving where the SC is not producing boost. Dan Matthew_Fiero MAY 21, 07:52 PM Ok thanks, I understand now. It IS like I imagined, but it didn't make sense that it would go to an outside relay just to come back to the C203 again.. just off hand, do you have any of those resistors? darkhorizon MAY 21, 08:36 PM I have a bunch of them... but you most likely dont want to mess with it.. You need to put a whole load of relays in to get the resistor working correctly, its sorta a pain. FIEROFLYER MAY 22, 08:14 AM The resistors are known to fail leaving you stranded unless you short out the connector to bypass the resistor but if you want to use one I have a few spares hanging over my work bench from GTP's and Regal GS's I have stripped. Dan Matthew_Fiero MAY 22, 10:46 AM I wont use one Matthew_Fiero MAY 22, 03:01 PM Do I still use the grn/blk wire to go to the pcm pin clear pin 3? FIEROFLYER MAY 22, 09:47 PM You mean the dark green with white wire for the fuel pump relay yes that is the +12 volts to turn on the fuel pump relay. Dan 1988Formula MAY 23, 12:01 AM On an 1997 GTP OBD II PCM would the first configuration i have drawn be the correct one that you are talking about above? I had originally thought that i only needed to run the wiring as drawn in the bottom configuration (in which case I would simply unplug the wire to pin 27 on PCM connector C1) Both configurations run to socket A on the fuel pump relay. Dan FIEROFLYER MAY 23, 08:46 AM The second one where the fuel pump relay is controlled by the one dk grn/white wire from the PCM. The second wire from the PCM for the speed cntrol controls another relay if you decide to use it. Basically if you are not using the dropping resistor the fuel pump is wired the same as the non super charged pumps. Dan