Fuel Pump Fuse Blows Intermittently

[hufhouse]

My son drives a 1996 Grand Am with the Quad Four engine.

Periodically...maybe three times a year...the fuel pump fuse blows. The previous owner, a family member, says this has been happening for years.

There doesn't seem to be any common cause. It has happened at idle and while driving down the street. It has happened in warm temps and cold. It has happened with a full tank or less than half a tank.

I know the fuel pump is on top of the gas tank and very hard to reach.

I searched the Grand Am forum and couldn't find this as a common problem.

Is there something else on this circuit? Where should I look for a short?

Tonight, he and his brother got stuck in a parking lot after guitar lessons. I left a supply of fuses in the car, so I walked them through replacing the fuse and they got home OK. I'd just feel more comfortable knowing what's causing the problem.

Thanks!

[tempfixit]

According to the electrical diagram I looked at, the oil pressure sending switch is part of the circuit. I would check the oil pressure switch and the wiring> I had the same thing happen on a 92 Regal, installed new oil pressure sitch and has not happened since.

Hope this helps

[hufhouse]

Thanks! I'll check that out.

[3100]

do voltage drop test at the FP relay (between gray and pink wire when engine is running) tell me what your result is. Also how many amps is the fuse that you are using for fuel pump? it should be 20A

[hufhouse]

Originally Posted by 3100

do voltage drop test at the FP relay (between gray and pink wire when engine is running) tell me what your result is. Also how many amps is the fuse that you are using for fuel pump? it should be 20A

We're definitely using a 20A fuse.

OK, I'm a real novice with the electrical meter. I have one (with the needle, not digital). What setting do I use? Do I just put one lead on the gray wire and one lead on the pink? What am I looking for in a "voltage drop test"?

Sorry. I could probably wire a whole house or build a home computer...I just never got "learned" in the ways of a multi-meter.

[3100]

exactly like that engine must be running to do that,

or you can just install new relay and see if the problem comes back.