Fuel pump?

Hi malibu1320, Welcome to 2carpros and TY for the donation

The fuel pump is in the fuel tank

You might want to inspect and test the vehicle speed sensor located in the transmission extension housing.

Hello,

The problem here is probably a short to ground in the fuel pump circuit. A short to ground will blow the fuse protecting the circuit because of laws governing electricity, Ohm's Law. Electricity can be broken down into three components, Voltage (Electrical pressure), Current/Amps (Electrical flow), and Resistance (Anything that opposes electrical flow). Ohm's law states that if one of the three components is constant (one always is in automotive electrical Voltage (12VDC) and another goes up (Amps) than the last one must go down (Resistance). This is a short to ground because the voltage is not making it to the load (fuel pump) because you have a bare wire somewhere touching ground. With no resistance the Amps (Electrical Flow) will go up until it overtakes the (20A) fuse and "pop" the fuse blows, just like it is designed to. Find the damaged wire in the circuit and repair it and you have fixed the problem.
I have included wiring diagrams for you in the diagrams down below with the fuel pump wires highlighted. Please find the short and get back to us with what you find out.

Thanks,
Alex
2CarPros

Couldn't find anything on going through the back seat, but here is a step by step for you.
Fuel Pump Removal

Disconnect the negative battery cable
Release the fuel pressure from the fuel system
Remove the gas cap
Drain or siphon the remaining fuel from the fuel tank, into an approved container
Raise and support vehicle
Disconnect the fuel line from the fuel filter
Disconnect the fuel line from the fuel pump
Disconnect the wiring harness from the fuel pump module
Position the transmission jack under the fuel tank for support
Remove the fuel tank straps
Lower the fuel tank for access to the fuel pump
Make sure the area around the fuel pump is clean; you do not want dirt particles going into the fuel tank after the fuel pump is removed
Using the fuel pump module ring spanner, remove the fuel pump lock nut
Remove the fuel pump o ring from the sealing area on the fuel tank
Back to top

Fuel Pump Installation

Clean the sealing area on the fuel tank
Install the new o ring on the fuel tank
Install the new fuel pump; make sure the alignment tab on the bottom side of the fuel pump module engages with notch in fuel pump
Install the fuel pump lock nut
Hold the fuel pump in place while tightening the lock nut to torque specifications
Using the transmission jack position the fuel tank back in place
Install the fuel tank straps, and tighten to torque specifications
Remove the transmission jack
Remove & install new fuel filter
Connect the fuel line to fuel filter
Connect the fuel line to the fuel pump module
Connect the wiring harness to the fuel pump module
Lower the vehicle
Refill the fuel tank
Install the gas cap
Reconnect the negative battery cable

A simple trick to finding a short is to replace the blown fuse with a pair of spade terminals, then use small jumper wires to connect them to a 12 volt light bulb. A brake light bulb works well. When the circuit is live and the short is present, the bulb will be full brightness and hot so be sure it's not laying on the carpet or against a plastic door panel. Now you can unplug electrical connectors and move things around to see what makes the short go away. When it does, the bulb will get dim or go out.

You take it to a mechanic who will diagnose it. He will figure out the cause of the problem, then tell you the name of whatever part is needed. There's no way I can know that if you aren't going to test anything. Mechanics don't have it that easy. If the fuse is labeled "fuel pump" logic dictates the fuel pump is shorted and that's the name of the part you want. Experience, however, shows that pumps rarely short so chances are you waste your money on a new pump because I told you the name of the part, then you're angry with me when the fuse still blows.

If you do my light bulb trick, as many intelligent mechanics would do, you can simply unplug the pump, then see if the bulb went out. If it did not, you know the short is still there and it's not the pump. Your choice if you want to spend money on something that very likely isn't needed.

There's actually two different fuses involved with the fuel pump circuit. The second one also feeds the ignition coil pack, injectors, alternator field, and oxygen sensor heaters. None of those things typical short either, and none of them are listed on that fuse. Most commonly a wire going to one of those things is grounded. You can spend all day tearing wire harnesses apart looking for that. Mechanics don't want to waste time that they have to charge you for, so they use my light bulb, then they just push and wiggle the wires to see what affects it. 95 percent of the time there is no part that needs to be replaced when a fuse blows. Most shorts are related to bare wires that are repaired.

That appears to be the pressure switch on the back of the AC compressor. That is in a different circuit than the fuel pump.

Hi there,

The fuel pump may be failing and over loading the fuse, they can check this by unplugging the pump and placing a test light in the circuit, if the fuse still blows on 20 Amp it will be in the wiring if not I would be considering the pump.

Mark (mhpautos)

Did you check for any applicable trouble codes? Did you check for voltage and ground at the pump connector for the motor? The dark green wire with white tracer is voltage for the pump motor, check with engine cranking. Black wire is ground. Also, do you have spark at the plugs? Injector pulse?

The voltage for the pump motor comes from the fuel pump relay in the power distribution center, under the hood. The computer may not be grounding the relay for some reason, that is why I asked you to check for applicable trouble codes. That is also why I asked you to visually check for spark at the plugs and injector pulse, engine cranking.

You can check for applicable mil codes, yourself. You cycle the key, no crank. Cycle the key on--off, on--off, on, then the mil starts flashing, you count the flashes to get the codes. Your looking for two digit codes.

At the pump relay diagram, terminal 55 is hot all the time. Terminal 56 is voltage for the coil side of relay, goes hot with the key in the crank position. Terminal 53 is ground for the coil side of relay, controlled by the pcm. When the relay is energized that line with the arrowhead switches to terminal 52, that terminal carries voltage to the fuel pump.