I got an after market fuel pump for my 1991 fc s5 ? do wires on the out side of the tank or the inside get spliced . there are four wires on the out side red ,black,black w/white stripe and green i have not opened the tank yet i an idea of what to do first .please help green mech.the new pump has 2 wires red , black thats the easy part the hard part is powering it red & blk on the inside or out.

 

It depends on the aftermarket pump, some are externally mounted and some are in-tank stock pump replacements.

In-tank pumps are powered be the wires inside the tank, externally mounted pumps can be spliced into the factory harness outside the tank or run directly to the relay/aftermarket ecu/etc

 

thanks I had an in tank it was simple once I opened the tank spiced the pos. & neg. and made some mods.