Q: What could cause fuse to keep blowing from fuel pump

asked by on

In April I replaced a fuel pump in my S10. When they replaced it , it blew a 20 amp fuse. They put in new fuse and it ran fine till this week. 5 months later. The fuel pump was bad and was replaced under warranty. It continues to blow fuse and they can't figure out what the problem is. Any suggestions?

My car has 160000 miles.
My car has an automatic transmission.

Fuses are over current protection devices which means that you either have a short to ground (possibly intermittent) somewhere in the circuit or enough added resistance in the circuit that the current drawn by the pump is enough to blow the fuse. You can use a volt ohmmeter to measure the current draw of the pump and see if it is within factory specified limits.

If you have a wiring problem, you can re-do (bypass) as much of the existing wiring as possible (i.e., re-wire the fuel pump circuit) because otherwise you will have to laboriously go over the entire circuit until you find the wiring fault.

You should also check to see whether the fuel pump is only device on the fused circuit. If not, check the other loads on the fuel pump circuit as those other loads could be causing the problem (the overload). To check that refer to wiring diagram in Factory Service Manual.

There is also the possibility of a physical (mechanical) restriction in the fuel pump tubing, filter and/or pick up causing the motor to overload and draw more current than intended. That’s why you should measure the actual current draw of the pump in normal operation to rule that out.

If you’re unable to perform these checks yourself, have a certified technician, like one from YourMechanic, come to you and diagnose the electrical problem firsthand for an accurate repair.

Was this answer helpful?
The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details
  1. Home
  2. Questions
  3. What could cause fuse to keep blowing from fuel pump

Get an instant quote for your car

Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Fair and transparent pricing

Get a quote

What others are asking

Q: Throttle body sensor

The throttle position sensor is an important input that the onboard computer uses to determine the proper amount of fuel to be added. A failing sensor can cause loss of fuel milage, engine stumbling, and reduced engine output are just...

Q: Is there anything else that causes accessories not to work besides a fuse besause I changed one bad fuse & still not working

The systems that are not working are powered through the battery saver relay actuated by the body control module. If one or more item shorted and blew out the fuse then no item will work. Check to make sure the...

Q: Chrysler 3.8 L. T&C power steering rack and pump replacement.

As you may know, the power steering rack pumps power steering fluid through a series of small reed valves that help to produce hydraulic pressure as the system is pressurized by the pump. This is what allows the power steering...

Related articles

How Long Does a Distributor O Ring Last?
The distributor is part of the ignition system in your vehicle and its purpose is to route high voltage from the ignition coil to the spark plug. The spark plug then...
P0240 OBD-II Trouble Code: Turbocharger Boost Sensor B Circuit Range/Performance
P0240 code definition Turbocharger Boost Sensor B Circuit Range/Performance What the P0240 code means P0240 is an OBD-II generic code triggered when the Engine Control Module (ECM) detects the intake boost...
P2103 OBD-II Trouble Code: Throttle Actuator Control Motor Circuit High
P2103 means there is a fault with the throttle actuator control motor circuit, likely due to a defective electrical component or part.