It there power to a fuel pump at all the time

Switch the horn relay with the c/op relay to see if it’s the relay. I don’t know why they have to give u complicated answers.

I would first suspect the fuel pump. Do you hear it buzz on for a couple seconds with turning the key to ON, not start?
It should come on for 2 seconds to prime the line with pressure to the engine. Do you hear it? Stand by the gas tank and have someone cycle the key to on if you need to.
If you hear nothing from the tank, you need to investigate the fuel pump and it's circuit.
There will be a fuse for the fuel pump, it is under the hood in the power distribution box-the fuse/relay block. The power for the pump goes from that fuse to the fuel pump relay (also in that fuse/block) and when the engine computer signals that relay on, the power goes through the relay and then directly to the pump in the tank.
Try this test, if your pump doesn't work-test the FPR-to test if the relay is getting a signal from the computer: hold your finger lightly on the relay. now have a helper cycle the key again from off to on (not start). Every time the key is cycled you should feel the click of the relay energizing. If you feel it click and you checked the fuse and it is good, and you still have no pump coming on, then it is likely you need a new pump. Bang on the bottom of the tank, a couple of raps, then see if pump turns on. A failing pump can sometimes be turned on by jolting it like this, but it only works a time or two or three.
So now what? If the pump is working and putting fuel to the engine, then check for spark at a spark plug. Usually a sudden no start means the engine has lost either gas or spark.

You have no voltage at 15 amp fuel pump fuse in the under hood fuse/relay center ? There is a fuel pump relay also in same under hood fuse box. The fuel pump fuse gets power from the fuel pump relay. The ( PCM ) engine computer controls that relay, gives power or ground electronically to turn the relay on giving power to the fuel pump through the fuel pump fuse. You could have a bad relay or an anti-theft system problem . What engine does you vehicle have 2.0 L or 2.2 L the 2.0 L engine gets power differently to fuel pump .

The click you hear is probably the fuel pump relay. See if you can locate it by sound. Possibly, the power feed for the pump may not be good at the relay. Pull the relay out and check for a power signal at one of the terminals that the relay plugs into. It should be a hot- at-all-times signal, so the key does not need to be on. The power feed will come from a maxi fuse in the power distribution box, or from a fusible link just off the battery. If the power is good, try another relay. If still no pump, check the wire from the relay to the pump for a short-a broken line. If wire is good, check the ground for the fuel pump.
Go back to your checking for power at the pump: just possibly, you missed the signal with the key on, because with key on the pump is only supposed to turn on for about 2 seconds (to pressurize the lines) and then shut off until the engine is cranked or running. Try testing for power again at the tank with the key held in start-should be a steady signal then, as long as the engine is cranking over. If still nothing, back to the relay. If you now have a signal for the pump when cranking engine, it must be the fuel pump ground.

Stand by the gas tank while someone turns the key to ON. Listen for the fuel pump to come on for a second or two as it should. It will only come on for about two seconds to pressurize the fuel system, then shut off and only come on again when the engine is cranked. If you hear it, then the pump is working. Hence, you would smell gas after cranking the car a bit. If no sound from the pump, look for the relay in the power distribution box under the hood. The box's cover should have a diagram for fuel pump location. Or your owner's manual might show it.

The first thing i would tey is changeing the fuel filter. Chevy has a problem with the design from the fuel pump to the fuel inlet on the intake manifold. What they did it is back up the power supply to the fuel pump from the fuel relay and split the curicut and ran the back up through the oil pressure sending unit . So even if the relay went bad while driveing the fuel pump would still get power and the truck wouldn't die on the road its a saftey thing .But if the relay is bad then the engine needs to build up enough oil pressure to trip the oil sending unit to send power to the pump from cranking thus a long cranking time when cold . Change the fuel filter first it should be replaced every 4 to 5 years anyway . A nd if that dosn't fix it try the relay it should be behind a panal inside the glove box on your truck and if that dosn't work replace the oil pressure sending unit. One of these 3 things should work if the fuel pump is working correctly

Fuel Pump Electrical Circuit
OPERATION
When the key is turned ON with out the engine running, the control module turns a fuel pump relay ON for two seconds. This builds up fuel pressure quickly. If the engine is not started within two seconds, the control module shuts the fuel pump OFF and waits until the engine starts. As soon as the engine is cranked, the control module turns the relay ON and runs the fuel pump.
When the engine is cranking or running, the control module receives the Crankshaft Position (CKP) sensor reference pulses which in turn energize the fuel injectors. As a back-up system to the fuel pump relay, the fuel pump can also be turned ON by a fuel pump oil pressure switch. When the
engine reaches about 28 kPa (4 psi), and the fuel pump relay does not complete the circuit, the fuel pump oil pressure switch will close to complete the circuit to run the fuel pump.

An inoperative fuel pump relay can result in long cranking times, particularly if the engine is cold. The fuel pump oil pressure switch will turn ON the fuel pump as soon as oil pressure reaches about 28 kPa (4 psi).



You can test to see if the relay it's self is bad by swapping it temporarily with another relay. If your truck has AC then that one should be compatible. Just compare the two to see if they're the same and if so, try using the AC's relay.

The fuel injectors receive their power from the Powertrain Control Module (PCM) Power Relay which is located in the Engine Compartment Fuse Box. This circuit is protected by Fuse "I" (20 Amp), also located in the Engine Compartment Fuse Box. If you blew a fuse, this would be the one.
The fuel pump, however, is a totally different circuit. (although it is controlled by the PCM which will not work if the fuse above is blown) The fuel pump gets its power from the fuel pump relay which is protected by Fuse "O" (20 Amp) in the Engine Compartment Relay Box.

when u checked this u do realize the fuel pump only has 12 volts for 1 second then the computer turns it off unless the engine is started? let me know.

Hi. Have you change the fuel pump relay?
If not change the relay, The original number is, RZ0088.
In the fuse box below the steering column. Is there a fuse for fuel pump.
The relay is a common problem for this cars.