Fuel pump fuse location

Hello,

ECM B fuse powers the fuel pump relay when the computer control of the relay coil energizes this is the time power will transfer to the fuel pump. Here is some diagrams (below) and guides to show you the location of the fuel pump fuse and to help you test the system and get it fixed.

https://www.2carpros.com/articles/how-to-check-a-car-fuse


Check out the diagrams (Below). Please let us know if you need anything else to get the problem fixed.

Electrical problem
1987 GMC Sierra V8 Four Wheel Drive Automatic

any thoughts as to why my 1987 gmc has no power to the fuel pump relay

Check and test the ECM B fuse if okay test the orange wire from the relay to the fuse holder

fuses check ok but there isnt any power in the orange from the relay to the fuse holder.

The wire is open-you suppose to have power at all times.

ok my bad there was a bad fuse replaced it and now i have power on the orange wire to the relay. now the switch that changes the tanks in the dash we think is bad. bought a new one and you have to hold the switch down to make the fuel pump run - the old switch does the same thing.

The initial problem was having to turn the ignition over two to three times before starting. That went on for about a month before truck died on the road. I changed the fuel pump. I tried starting the truck with no susccess. After that I changed the fuel pump relay. Still nothing. I dropped the fuel tank again and checked for voltage to the pump. There was no voltage. I checked the relay to see if the relay was good. Yes it Is a good relay. The wiring schematics indiacate power should be coming from the PCM. That is where I am at. Stuck! Do I replace the PCM?

Welcome, thanks for the donation, did you check for voltage at the pump with engine cranking? Other than the initial prime, the pump won't run without rpm signal. You can pull relay, use teslite at relay terminals, see how many hot terminals, engine cranking. The load side of relay gets voltage from ecm b fuse. Voltage for coil side of relay does come from pcm.

Are the gray (86) and black/white (30) wires switched on the fuel pump relay circuit? Ive been trying to find this out everywhere! So, to clarify, the gray wire needs to be in the 30 position, right? Essentially moving the black/white wire to the 86 position? Or are they oriented correctly? I had to flip it to snap the pic so the fuel pump relay wires are in the top left corner. I am pretty sure that the other wires are correct. any help would be greatly appreciated thank you

No, pin 30 is the power supply coming into the relay on the orange wire. The gray wire is the power out to the fuel pump on pin 87. Pins 85 and 86 are the control wires that operate the relay.