Fuel Pump Will Not Come On

[ddgordan]

1988 Full Size Blazer - Have Replaced The Fuel Pump And Fuel Pump Relay. Fuel Pump Does Not Energize When Key Is Turned On. I Understand That There Is A Fuse For The Fuel Pump But Cannot Locate? Also That The Oil Pressure Switch Affects The Operation Of The Fuel Pump? Any Ideas Or Direction Would Be Greatly Appreciated ....

[tom3]

Oil pressure switch is a failsafe deal. Try running the starter for several seconds and see if the engine will then start with the pump running on the pressure switch. Fuse, I think, is either in the fuse box under the dash just above where the clutch pedal would be, might have a cover to remove. On the 88 I think there is a grey wire just above the heater box out under the hood, hanging out of the wire harness with a connector not connected to anything. This is a fuel pump prime wire and will send power direct to pump, try putting 12 volts to this wire and see if pump will run.

[RABarrett]

You might want to check the post I submitted in the Astro area recently. It contains a detailed description of the duel delivery system, including the contribution of the oil pressure switch. Ray

[ddgordan]

Thank you, Ray/Tom for the additional ideas. Much appreciated!