Fuel pump fuse

BETH40965

MEMBER
2005 CHEVROLET EQUINOX
6 CYL
4WD
AUTOMATIC
140,000 MILES

Car was missing for a week or longer just sometimes, then it started missing bad like going to cut off so I turned the car off and it wouldn't start, it would turn over and try to start then cut right back off. Someone put a fuel pump fuse in it because the one in was blown and it started right up. I thought I felt a miss the next day but didn't do it again yet. So wondering what caused it and what should I do replace the fuel pump or should it be fine now?

2 Replies

BETH40965

MEMBER
2 POSTS

Before all this happened when it would miss and cut out bad while driving for about thirty seconds and the check engine light would blink.

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Friday, April 12th, 2019 AT 8:41 AM

SCGRANTURISMO

MECHANIC
4,897 POSTS

Hello,

What you probably need to do is trace the fuel pump (12 volts) wire from the fuse and see where the short to ground is. The reason that a fuse that is protecting a circuit blows is called a short to ground. This happens because of the laws governing automotive electricity called Ohm's Law. Electricity has three components to it(1 - Voltage(Electrical Pressure-like PSI in a hose for liquid) 2 - Current/Amps(Electrical Flow(Like water through a hose) 3 - Resistance(Anything that opposes current(like a blockage in a hose for liquid). Ohm's law states that if one of the three electrical components is constant, and one always is in automotive electrical circuits, Voltage(12VDC-Battery Voltage), then when one of the other two decreases Resistance(Bare wire before circuit load touching ground making resistance drop to zero) than the last component must increase Amps(which is now flowing infinite as opposed to zero). As soon as the amps over take the fuse protecting the circuit, the fuse will "pop" and protect the circuit by creating an open and stopping the current/amp flow. If the wire, or more specifically, the short to ground is not fixed, then the same thing, eventually, will happen again.I have included a wiring diagram of the fuel pump circuit in the diagrams down below. Please find the short to ground and get back to us with what you are able to find out.

Thanks,
Alex
2CarPros

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