I have a '78 SR5 PU with the 20R engine I drove to a restaurant, and when I came out, the truck would start and immediately die. I remembered having this problem before and it was the fuel pump. (I have had the truck since new) So, I dropped the tank and found out the pump would run when power was applied. I have checked the pump relay and there is no power to the relay. The resistor under the hood is OK, but there is no power to the resistor. I tried applying power to the resistor but still no luck. I am unable to trace the wire from the ign. switch to the resistor. I suspected a fuse but all the fuses in the fuse block are OK. My only circuit diagram is from an aftermarket repair manual. I have the service manual set but the circuit diagrams are not for this truck for some reason. Before I install an aftermarket electric fuel pump I thought I would ask the forum for ideas. I really hate to be defeated by this! Thanks, Chuck
Hmm... I just switched from my aftermarket to stock just a couple weeks ago...my resistor was bad (and i went out and got a new pump ). You disconnected the oil pressure switch during all this (just double checking)? If you have no power following the resistor when the ignition is ON, i'm pretty sure it must be the wiring from ignition switch. your dash lights do come on though, correct?
