Fuel pump power
Asked by Craft357 Jun 06, 2017 at 10:59 PM about the 1995 GMC Sierra 1500 C1500 SLE Extended Cab LB
Question type: Maintenance & Repair
Good evening, I am seeking advice about my truck.
I changed the oil sending unit and now I have to
hardwire my fuel pump to the battery. It takes a lil
time for my truck to start. The relay is new. Does
anyone know what it could possibly be?
5 Answers
Was fuel pump coming on before you swapped oil pressure switch. If not. Check the ground on frame. Might just need to clean up the ground location. Was other switch leaking
I am losing oil from around that area. This was the reason why I changed it.
Before hard wiring. Recheck connection on oil pressure switch. That has to energize before fuel pump will come on. With switch on. Orange wire on. Oil pressure switch should have power and the grey should have power. 12 volts on both. The Orange wire on sending unit is powered by ecm b fuse under the hood junction block. If no power on grey wire coming from oil pressure switch. Engine will not start. If you do have 12 volts on grey check your fuel pump relay.
I'll check but I did replace the relay with a new one