I have a 2003 GMC sierra C1500 HD. need to replace fuel pump.

SOURCE: in-the-tank fuel pump r&r

Here are instructions for replacment with a diagram of the fuel pump components my only suggestion would be instead of draining the tank and dropping the fuel tank if you unbolt the box and using a jack and and some wood lift the fuel tank side of the box this will give you access to the tank and fuel pump/ sending unit. It will save you time and the hastle of replacing the tank straps which are prone to snapping at the threads when trying to remove the nuts.If these brake you will have to replace them.

SOURCE: 1997 gmc sierra p/u 5.0l 2wd needs fuel pump

NO dont drop tank, you will be sorry, take bed off, only like 6 or 8 bolts, and you will have more room to work, and its a pain in the *** to undo the lines and drop the tank, you cant get in there to do it, but just basic tools nothing special, be sure and try not to make any sparks while takein off that ring to get the pump out, and put an ac delco pump on there

SOURCE: fuel pump fuse located on 1997 gmc sierra

The fuse is actually a Relay Switch and its located in the Fuse Relay Center on the driverside of the engine compartment. The Black Box is labled Fuse Relay Center, the diagram on the cap displays which Relay is the Fuel Pump relay...the Relay switch is usually $8-$15 depending on where you shop

SOURCE: Need to replace blower motor in 1995 GMC Sierra sl

On the passenger side. Right on top of the black plastic housing. You have to take the glove box, dash, etc. to get it out.
a couple of bolts and disconnect harness and it shouldnt be to hard

SOURCE: wiring diagram 2003 GmC Sierra

I need wiring digram for GMC 2003 SIERRA . I have the left head light working fine but the right I have no power to it. I have checked the fuses and relaysand so far have not found and broken or frayed wires.