Fuel pump not pumping

Thye fuelpump relay is located to the right of the brake booster. this is for a 1991 gmc jimmy (s-15)

I have enclosed a diagram to help locate the relay.

The most common reason for no fuel pressure on these trucks is not the relay but rather the fuelpump itself. the pump is located inside the fuel tank.

There is also a problem with the wiring to the fuel pump, you will need to locate the top of the tank and then off to side of tank is wiring .
This wiring comes off the top of the tank, you will need to check and there is connector problems..
there is one or two ground wires that come off wiring to top of tank which run to frame, check to make sure the grounds are good. if you end up with a bad pump you will see a notice to rewire a new fuelpump connector. hope this is helpful. good day.

Fuel pump relay inside the glove box is kaputz? http://www.ehow.com/how_5486354_replace-jimmy-fuel-pump-relay.html

did you change feul filter? some of these will install backwards and will have no flow.is there enough feul in tank? did you replace or clean sock at bottom of feul pump

CHECK TO SEE IF FUEL PUMP IS CYCLING WHEN YOU TURN KEY ON, SHOULD HEAR BUZZING NOISE FOR 5 TO 10 SECONDS,IF NOT FUEL PUMP IS FAILING.

pull line off of front of filter and cycle key 2 on position if there is no fuel present your feul pump may b the problem, before replacing old one make sure the fuse is good

If you need further help, I’m available over the phone at https://www.6ya.com/expert/michael_00678fd4800d19c5

Sounds like the relay is not shutting off fuel pump. Turn the key to on position ( not start ), pump should only run for a few secounds and you will hear a click and pump should shut off, if it keeps running relay is bad. If it works like it should than fuel regulator (if there is one) would be the next posability.

id say the fuel pump isnt working as it sounds...id replace the fuel pump

Many wires on most autos will have low voltage around 5 volts is common for wires going to most sensors. What you described with the fuel pump sounds normal for this truck. I would guess the fuel pump is not your problem cant say for shore with out any more info. I am unclear as to what the symptoms are, is the truck not starting. What led you to check the fuel pump. Did you check for spark.

Check the fuel pump.

The fuel is in a continous loop being available at  all times to the TBFI. It has the return path so it can always return to the tank via the return line. Np check valve as the pump runs all the time.