FUEL PUMP ALWAYS ON

[Scwhitten]

Ok, so you know when you turn the key to ON you hear fuel pump come on for a few seconds then shut off (at least I think that's what's supposed to happen)? Well when I turn the key to ON, I hear it, but it doesn't stop. Even after the car has started, I can still hear it from several feet way. Can anybody help me with this? The pump is new. I know people might want to jump right on that and say it came bad from the factory, but I just don't believe that is the case.


Thank you.....Scott
2001 Mustang GT
Only owner.

 

[Scwhitten]

Ok, so you know when you turn the key to ON you hear fuel pump come on for a few seconds then shut off (at least I think that's what's supposed to happen)? Well when I turn the key to ON, I hear it, but it doesn't stop. Even after the car has started, I can still hear it from several feet way. Can anybody help me with this? The pump is new. I know people might want to jump right on that and say it came bad from the factory, but I just don't believe that is the case.


Thank you.....Scott
2001 Mustang GT
Only owner.

I will add that the tank is on Empty, there is enough gas to start it, but it's basically empty. Not sure if that matters.

 

[nickyb]

New or old pump shouldn't matter, full or empty either way the ecu sends power the pump to prime then shuts it till the engine is running.
Your constant running is somewhere in the wires ,ecu, relay?

 

[Scwhitten]

New or old pump shouldn't matter, full or empty either way the ecu sends power the pump to prime then shuts it till the engine is running.
Your constant running is somewhere in the wires ,ecu, relay?

Yes, thank you for responding. The fuse is fine. I looked for the relay but my Chilton's doesn't talk about it other than showing it in the wiring diagram for the whole electrical system. YouTube says it is in the same box as the fuse but in my car, it is not. There are 5 relays in my fuse box (under the hood adjacent to the battery), none of them are the fuel pump relay, according to the owners manual that came with the car.

Would you know where it is In my car, 01 GT? I saw something about a relay behind the glove box, but I didn't think it was my model car.

Thanx again nickyb.

 

[Mcmahst]

Try this:

1994-2004 SN95 & New Edge Mustang Fuel Pump Relay Location

A big issue that many SN95 and New Edge Mustang owners have is finding their fuel pump relay location. So, we at LMR have provided a quick location guide.

lmr.com

 

[Scwhitten]

Try this:

1994-2004 SN95 & New Edge Mustang Fuel Pump Relay Location

A big issue that many SN95 and New Edge Mustang owners have is finding their fuel pump relay location. So, we at LMR have provided a quick location guide.

lmr.com

Seriously? Why would they put in there, in a hidden box, sealed with rivets, then soldered to circuit board??? Great!!!!

So under the video, it says..."Most fuel pumps emit a low-pitched hum or whine that can be detected from within the car if you listen carefully or from the outside of the car, close to the fuel tank. When the fuel pump relay malfunctions, power will be cut off, rendering the pump inoperable and silent when the ignition is turned on." My problem is that fuel pump is only silenced with the key is in the OFF position.

So, not the relay?

Thanx Mcmahst for your response...

 

[Mcmahst]

IDK, but you can probably test voltages from the box to determine if power is constant to the pump. Now, I’m not any kind of knowledgeable person on these years of Mustangs. You’ll need someone who knows the diagnosis steps to deal with this. Also, have you checked for codes? Most of the time, we skip that critical step. Good luck.