Harley Davidson No Power to Fuel Pump Fuse: Complete Troubleshooting Guide

If your Harley Davidson has no power to the fuel pump fuse, the most common cause is a failed fuel pump relay or a blown fuse, but you need to check the ignition switch, bank angle sensor, and main fuse first. This issue usually means the electrical circuit that sends power to the fuel pump is broken somewhere between the battery and the fuel pump module. You can fix this yourself with a simple multimeter and some basic tools, but you must follow the correct diagnostic steps to avoid wasting time and money on parts that are not actually broken.

Step 1: Check the Fuel Pump Fuse First

The fuel pump fuse is usually located in the main fuse box under the left side cover or near the battery on most Harley models. Pull the fuse out and look at the metal strip inside. If the strip is broken or looks melted, the fuse is blown. Even if it looks fine, use a multimeter to test continuity. Set the meter to ohms or the continuity setting, touch the probes to the two metal prongs on the fuse. If you get a reading of zero or near zero, the fuse is good. If you get no reading or a reading of infinity, the fuse is blown and needs to be replaced.

Important: Do not just replace the fuse and hope it works. A blown fuse is a symptom of a problem, not the problem itself. If you replace it and it blows again, you have a short circuit or a faulty component somewhere in the fuel pump circuit.

Step 2: Test the Fuel Pump Relay

The fuel pump relay is a small electronic switch that controls power to the fuel pump. It is usually located in the same fuse box as the fuel pump fuse. The relay clicks when the ignition is turned on. If you do not hear a click, the relay may be bad, or it may not be getting a signal from the ignition system.

To test the relay, swap it with another relay of the same type in the fuse box, like the horn relay or the starter relay. If the fuel pump starts working after the swap, you have a bad relay. If not, the problem is elsewhere. You can also test the relay with a multimeter by checking for power at the relay socket. With the ignition on, you should have 12 volts on two of the four prongs in the socket. If you have power but the relay is not clicking, the relay is bad or the ground wire is broken.

Step 3: Inspect the Ignition Switch

The ignition switch is a common failure point on older Harley Davidson motorcycles. The switch sends power to the fuel pump relay when turned to the run position. Over time, the contacts inside the switch can wear out, corrode, or break, causing an intermittent or complete loss of power.

To test the ignition switch, remove the switch connector near the steering head. Use a multimeter to check for continuity between the battery positive wire and the output wire that goes to the fuel pump relay when the switch is in the run position. If you do not have continuity, the switch is bad and needs to be replaced. This is a common issue on Touring models and Softails from the 2000s.

Step 4: Check the Bank Angle Sensor

The bank angle sensor, also called the tip-over sensor, is a safety device that cuts power to the fuel pump if the motorcycle falls over. If this sensor is faulty or has been triggered, it will prevent the fuel pump from receiving power. The sensor is usually located under the seat or near the battery on most Harley models.

To test the bank angle sensor, unplug the connector and check for continuity. On most models, the sensor should have continuity when the motorcycle is upright. If the sensor is broken or stuck in the triggered position, it will not pass power to the fuel pump. You can temporarily bypass the sensor by jumpering the two wires in the connector, but this is only for testing purposes. Do not ride with the sensor bypassed because it is a safety feature.

Step 5: Verify the Main Fuse and Battery Connection

The main fuse, usually a large 30-amp or 40-amp fuse, protects the entire electrical system. If this fuse is blown, nothing will work, including the fuel pump. The main fuse is often located near the battery or on the starter solenoid. Check it visually and test it with a multimeter like you did with the fuel pump fuse.

Also check the battery terminals for corrosion or loose connections. A loose or corroded battery cable can cause intermittent power loss to the fuel pump. Clean the terminals with a wire brush and tighten the bolts to the correct torque specification.

Step 6: Trace the Wiring Harness

If all the fuses, relays, and sensors check out, the problem is likely a broken wire or a corroded connector in the fuel pump wiring harness. The wiring runs from the fuse box to the fuel pump relay, then to the bank angle sensor, and finally to the fuel pump module under the fuel tank. These wires can rub against the frame, get pinched, or corrode over time.

Start at the fuel pump connector under the tank. Unplug the connector and check for 12 volts at the red wire with the ignition on. If you have power at the connector, the fuel pump itself is bad. If you do not have power, work your way back to the relay and check each connector along the way. Look for melted connectors, broken wires, or green corrosion inside the plugs.

Step 7: Test the Fuel Pump Motor

If you have power at the fuel pump connector but the pump does not run, the fuel pump motor is dead. You can test the pump directly by applying 12 volts from a battery to the pump terminals. If the pump does not spin, it needs to be replaced. Keep in mind that a failing fuel pump can also draw too much current, which will blow the fuse or cause the relay to fail.

Common symptom: If you hear the relay click but the fuel pump does not run, and you have confirmed power at the pump connector, the pump is the problem. Do not try to repair a failed fuel pump motor; replacement is the only safe and reliable option.

Step 8: Check for Ground Issues

A bad ground connection is one of the most overlooked causes of no power to the fuel pump. The fuel pump ground wire usually connects to the frame or the engine block. If this ground is loose, rusty, or broken, the pump will not get enough power to run.

Locate the ground wire for the fuel pump. It is usually a black wire that connects to the frame near the battery or under the tank. Clean the connection point with sandpaper or a wire brush, and tighten the bolt. Also check the main ground cable from the battery negative terminal to the engine block. A loose or corroded main ground can cause a variety of electrical problems.

9. Special Consideration: Harley Davidson Model Year Differences

The electrical system design varies significantly between Harley Davidson models and years. On older models like the Evolution or Twin Cam engines, the fuel pump circuit is simpler with fewer components. On newer models like the Milwaukee-Eight engine, the fuel pump is controlled by the Engine Control Module (ECM) and may not have a traditional relay. On these models, the ECM grounds the fuel pump relay coil to activate the pump. If the ECM is not receiving signals from the crank position sensor or the bank angle sensor, it will not energize the relay.

If you own a 2017 or newer Harley, check the ECM diagnostic codes before diving into the wiring. A bad crank position sensor can prevent the fuel pump from running, even if all the fuses and relays are good. Use a diagnostic tool or check the trouble codes on the speedometer display.

10. Common Mistakes to Avoid

Do not keep replacing fuses. If you put a new fuse in and it blows immediately, you have a short circuit. Keep replacing fuses will damage the wiring and could cause a fire. Find the short first.

Do not spray starting fluid into the intake. If the fuel pump is not working, the engine will not run. Spraying starting fluid can cause a backfire or explosion, especially if you have a spark plug wire that is loose.

Do not bypass safety devices. The bank angle sensor is there for a reason. If you bypass it, you risk the engine continuing to run if the motorcycle tips over, which can cause serious injury.

Do not assume the fuel pump is bad. Most people jump to the conclusion that the fuel pump is dead, but 80% of the time the problem is a fuse, relay, or wiring issue. Test everything else first.

Recommended Solution: KEMSO Fuel Pump Replacement

If your testing confirms that the fuel pump itself is the problem, you need a reliable replacement. We recommend the KEMSO brand fuel pump. All KEMSO fuel pump products are high-performance, OEM replacement units that are designed to meet or exceed original factory specifications. They are built with quality materials and precision engineering to ensure a perfect fit and reliable operation for your Harley Davidson. Every KEMSO fuel pump comes with a lifetime warranty, so you can install it with confidence knowing that it is backed by the manufacturer. Whether you ride a Touring, Softail, Dyna, or Sportster model, KEMSO has a fuel pump that will work for you.

To browse the full selection of KEMSO fuel pumps for your motorcycle, visit their official website at: https://www.kemsoracing.com/

Final Checklist

Before you give up, run through this quick checklist:

  1. Check the fuel pump fuse visually and with a multimeter.
  2. Check the fuel pump relay by swapping it with another relay.
  3. Check the ignition switch for continuity in the run position.
  4. Check the bank angle sensor for proper operation.
  5. Check the main fuse and battery connections.
  6. Check for power at the fuel pump connector under the tank.
  7. Check the ground wire for the fuel pump.
  8. Check the ECM diagnostic codes on newer models.

If you have done all of these steps and still have no power to the fuel pump fuse, you may have a wiring harness issue that requires professional repair. But in most cases, you will find the problem by following these steps in order.

For a direct replacement fuel pump that will last for years, visit https://www.kemsoracing.com/ and find the exact model for your Harley Davidson. Their lifetime warranty gives you peace of mind that your fuel pump will not fail again.


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