* Faulty Fuel Pump: This is the most likely culprit. A failing fuel pump can draw excessive current, causing the fuse to blow. This might be due to a worn-out motor, internal shorts, or simply age.
* Wiring Problems: Damaged, frayed, or corroded wiring in the fuel pump circuit can cause a short circuit, blowing the fuse. Check the wiring harness from the fuse box to the fuel pump for any signs of damage, especially near the tank. Rodents can sometimes chew on wiring too.
* Fuel Pump Relay: While less common, a malfunctioning fuel pump relay can also cause the fuse to blow. The relay acts as a switch for the pump, and a faulty one can send too much power.
* Short to Ground: A short circuit to ground in the fuel pump wiring can overload the circuit and blow the fuse. This could be due to a wire rubbing against the chassis or other metal components.
* Low Fuel Level Sensor: In some cases, a problem with the low fuel level sensor can cause a surge of current that blows the fuse. This is less common but possible.
* Fuel Pump Inertia Switch: Many cars have an inertia switch that cuts power to the fuel pump in the event of a collision. If this switch is tripped (usually located under the dash or in the engine bay), it might need to be reset.
* Improper Fuel Pump Installation (if recently replaced): If the fuel pump was recently replaced, it might have been installed incorrectly, leading to shorts or other problems.
Troubleshooting Steps:
1. Check the Fuse: First, check the fuel pump fuse itself. Make sure it's the correct amperage and replace it with a new fuse of the same rating. If it blows immediately after replacement, you have a short circuit somewhere in the system.
2. Check the Fuel Pump Relay (if applicable): If your Buick uses a relay for the fuel pump, try swapping it with a known good relay (if you have one).
3. Inspect the Wiring: Carefully inspect all wiring related to the fuel pump, looking for any signs of damage, corrosion, or chafing. Pay close attention to the wiring near the fuel tank.
4. Check the Inertia Switch (if applicable): Locate the inertia switch and check if it's tripped. If so, reset it.
5. Check the Fuel Pump Directly (advanced): This requires some electrical knowledge. You can test the fuel pump's resistance using a multimeter to determine if the pump itself is faulty. Caution: This involves working with potentially explosive fuel; exercise extreme caution and follow appropriate safety procedures.
If you're not comfortable performing these checks, it's best to take your Buick Century to a qualified mechanic for diagnosis and repair. Continuing to replace fuses without fixing the underlying problem could damage other components in the electrical system.
