92 Regal blowing fuse pump fuse

[tempfixit]

I have replaced fuel pump,(Did NOT replace fuel gauge assembly pump and pick up screen only) fuel filter and fuel pump relay. Drove vehicle for about 15 miles no problem, mother in law drove it for a few miles yesterday again, no problems. Today went to start and fuel pump/ECM fuse under hood blown again. Has anyone had the problem of the ECM blowing the fuse?? Does anyone know where the Fuel pump Prime Connector is located??
Will a fuel gauge assembly cause fuse to blow???

Originally fuse blew, replace fuse and drove vehicle fuse blew after engine warmed up, replace fuse and started right back up. The pump did have 48 lbs. pressure. I thought the pump when running for a period of time heated up and required more amperage causing fuse to blow.

Any suggestions on what to do next would greatly be appreciated as I am stumped.

[Blue Bowtie]

My guess is that there is a problem with the fuel pump circuit, and not the pump itself. Testing the pump circuit amperage with a fully warmed pump might verify that. If the pump current is well below the fuse rating (as it should be) the problem is likely elsewhere. There could be bare/exposed wiring which shorts or grounds when the vehicle is driven and the wiring moves, or other parts of the circuit could have problems.

The fuel pump prime (test) connection is the "G" terminal of the ALDL connector under the dash.



The wiring for that circuit could be a problem, but that circuit is essentially inactive when the fuel pump relay is energized, since it operates through the N.C contacts of that relay.



Still, it might be good to investigate that with the other potential wiring shorts/grounds.

The other devices in that same circuit are the ECM main power and auxiliary oil pressure switch (used to power the fuel pump). Wiring problems to those devices, or failures of those devices can cause fuse failure. The oil pressure switch is a prime suspect in this case, since that same switch assembly is used to ground the oil pressure warning light in the instrument panel.

[Mickey#1]

I'd check the oil pressure sender 1st.

[tempfixit]

Thanks Blue Bowtie and Mickey#1 for your help. The wiring diagram I looked at in autozone.com only showed the fuel pump, fuel pump relay, and fuel pump prime connector going to the ECM. BY the way I missed mentioning that it is 3.8 L engine Regal Custom if that makes a difference. I will check all you guys suggested. Thanks again

[tempfixit]

UPDATE: The oil pressure switch had shorted and burned the wiring connected to it. Have not had any problems since fixing. Thanks again for your advice and help Blue Bowtie and Mickey#1

[Kacy]

Originally Posted by tempfixit

UPDATE: The oil pressure switch had shorted and burned the wiring connected to it. Have not had any problems since fixing. Thanks again for your advice and help Blue Bowtie and Mickey#1

I had the EXACT same problem as tempfix. When the car warmed up it would blow the ECM/FUEL fuse. I replaced the oil pressure switch and the burnt wires going to the oil pressure switch. All works GREAT now. You guys saved me SOOOO much time and money! Thank You, Thank You, Thank You!