* Related Circuits: The fuel pump and transaxle (automatic transmission, I assume) are both significant power consumers and likely share some common wiring or power sources. A short in one circuit can easily affect the other, especially if there's a common ground wire problem.
* Possible Causes of Blown Fuel Pump Fuse:
* Short in Fuel Pump Wiring: The most likely culprit. A wire chafing against the chassis, a damaged connector at the pump itself, or even a faulty fuel pump motor could cause a short, drawing excessive current and blowing the fuse.
* Short to Ground: A wire in the fuel pump circuit might have rubbed against a grounded part of the car, creating a direct short.
* Faulty Fuel Pump Relay: Although less common, a stuck-on fuel pump relay could also draw excessive current and blow the fuse. This is less likely if the transaxle fuses also lack power.
* Wiring Harness Damage: Damage to the main wiring harness, possibly from rodent damage or a previous repair, could be affecting multiple circuits.
* Possible Causes of No Power to Transaxle Fuses:
* Related Short Circuit: As mentioned, a short in the fuel pump circuit could disrupt the power supply to other circuits, including the transaxle, especially if they share a common power source or ground.
* Main Power Wire Issue: A problem in the main power feed to the fuse box could affect multiple fuses. This could be a loose connection, corroded terminal, or a damaged wire in the main harness.
* Faulty Fuse Box: While less common, a problem within the fuse box itself could interrupt power to certain circuits.
Troubleshooting Steps (in order of safety and simplicity):
1. Safety First: Disconnect the negative battery terminal before doing any electrical work to prevent accidental shorts and shocks.
2. Visual Inspection: Carefully examine all wiring related to the fuel pump and the transaxle. Look for:
* Chafed or damaged wires: Pay close attention to areas where wires might rub against metal parts of the car.
* Corrosion on connectors: Clean any corrosion you find with a wire brush and electrical contact cleaner.
* Loose or broken connectors: Secure any loose connections.
3. Check the Fuel Pump Relay: If accessible, visually inspect the relay and try swapping it with a known good relay of the same amperage and configuration (check your owner's manual).
4. Check the Fuel Pump Directly (Advanced, requires caution): If you're comfortable with electrical systems, you can test for continuity and voltage at the fuel pump connector. Only do this with the fuse removed.
5. Check for Power at the Fuse Box: With a multimeter, check for power at the input side of both the fuel pump and transaxle fuses. This helps isolate whether the problem is before or after the fuses.
6. Ground Check: Investigate the car's ground points. Poor grounding can cause erratic electrical behavior. Check for corrosion or loose connections at the ground points near the fuel pump and transmission.
7. Professional Help: If you're not comfortable with electrical diagnostics, it's best to take your Saturn to a qualified mechanic. This issue could be more complex than it appears and could lead to further damage if improperly diagnosed.
Important Note: Continuing to replace the blown fuel pump fuse without addressing the underlying short circuit will only result in more blown fuses and potential damage to the electrical system. Find and fix the short!
