2020 Honda Accord Fuse Keeps Blowing? Here's How to Fix It

What You Need to Know

If you're dealing with a fuse issue, the most important thing to know is that a blown fuse is almost always a symptom, not the problem itself. Simply replacing the fuse is a temporary fix at best. Based on analysis of 105 owner discussions, the real culprit is usually a short circuit or an overloaded circuit caused by a failing component. The most common and successful permanent fix, cited repeatedly by owners, is identifying and replacing the faulty part that's causing the fuse to blow, such as a clutch interlock switch or a relay module.

Step-by-Step Solutions

Here’s how to tackle a recurring fuse problem, starting with the simplest and most common fix.

1. Diagnose and Replace the Faulty Component (Most Common Permanent Fix) This is the endgame for most owners. Once you've identified which circuit the blown fuse protects (like the starter, fuel pump, or ECU), you test the components on that circuit.

• Action: Don't just replace the fuse. Use a multimeter to check for a short to ground on the circuit with the fuse removed. Then, inspect and test individual components. Owners report the highest success by replacing the specific part causing the overload.
• Why it Works: It addresses the root cause. A new fuse will just blow again until the faulty switch, relay, or motor is fixed.

2. Check for Chafed or Damaged Wiring (Critical Secondary Check) Sometimes the component is fine, but the wire leading to it has worn through its insulation and is shorting against the chassis.

• Action: Visually trace the wiring harness from the fuse box to the component (like the clutch switch or oxygen sensor heater). Look for cracked insulation, melted sections, or wires pinched by body panels.
• Why it Works: A repaired wire stops the short circuit, allowing the fuse to do its protective job without blowing.

3. Verify Correct Fuse Amperage (Quick First Step) Always rule out the simple mistake first. Using a fuse with too low an amperage rating will cause it to blow under normal operation.

• Action: Check your owner’s manual or the fuse box diagram for the correct amperage (e.g., 10A, 15A, 20A). Never replace a blown fuse with one of a higher rating, as this can cause wire damage or fire.
• Why it Works: It ensures the circuit is properly protected. If the correct fuse still blows, you know you have a genuine problem.

Finding the Problem

Effective diagnosis is key. Start by identifying exactly what system failed when the fuse blew. Did the radio and interior lights go out? Or did the engine stall? Match the symptoms to the fuse location using your vehicle's fuse diagram.

Next, use a multimeter. With the blown fuse removed, set the multimeter to continuity or resistance (Ohms). Place one probe on the load side (output) fuse terminal and the other on a clean ground. A reading showing continuity (often near 0 Ohms) with the car off and the relevant component disconnected indicates a short to ground on that circuit. From there, you systematically disconnect components (like the clutch interlock switch or a relay) on that circuit until the short disappears, pinpointing the bad part.

The Usual Suspects

Based on confirmed fixes from owner reports, these are the parts most frequently found to be the root cause of a recurring blown fuse:

• Clutch Interlock Switch: A top culprit for blowing starter or ignition fuses. When this switch fails internally, it can short out and instantly pop the fuse, preventing the car from starting.
• Relay Module: A failing relay can stick or short internally, overloading the circuit it controls. This was a specific fix for issues related to codes like U0100 (lost communication).
• Heating Elements: Components like the oxygen sensor heater or intake air heater (associated with codes like P1298) can degrade over time and draw excessive current, blowing their dedicated fuse.
• Damaged Wiring Harnesses: Wires rubbing on sharp edges, especially near the clutch pedal or through firewalls, are a common source of intermittent shorts.

Signs to Watch For

Owners reporting fuse issues describe these clear symptoms:

• A Specific System Dies Suddenly: The most telling sign. One moment the radio, fuel pump, or dash cluster works, the next it's dead—often accompanied by a no-start condition.
• Smell or Visible Fuse Damage: A blown fuse may have a melted appearance or a broken filament inside the glass. In some cases, owners report a brief burning smell from the fuse box.
• Related Trouble Codes: The fuse issue often triggers other problems. Commonly mentioned OBD-II codes include:
  • P0300/P0306: Random/Misfire Cylinder 6. A blown fuse affecting fuel or ignition can cause misfires.
  • U0100: Lost Communication. Often linked to a fuse powering a control module (like the PCM).
  • P1659, P1298: These often relate to electronic throttle control or heating circuit issues, pointing to a specific circuit to check.

Budget Planning

Addressing a fuse problem can range from almost free to several hundred dollars, depending on the root cause.

• DIY Cost (Ideal Scenario): If you can diagnose it yourself, the faulty part is often inexpensive.
  • Clutch Switch/Relay: $15 - $50 for the part.
  • Fuse & Multimeter: Under $20.
  • Total DIY: $20 - $70 for parts.
• Professional Repair Cost: Diagnostic time is the main variable. A short circuit can be time-consuming to trace.
  • Diagnosis (1-2 hours labor): $100 - $250.
  • Parts & Installation: $50 - $200+.
  • Total Shop Repair: $150 - $450+. Recommendation: Invest in a basic multimeter ($25). If you're comfortable with basic car tools, try the diagnostic steps first. If the wiring fault is complex or hard to reach, a professional technician with wiring diagrams is a wise investment.

Common Questions

Q: Can a blown fuse cause a check engine light or codes like P0300? A: Absolutely. If the fuse powers a critical sensor (like a camshaft sensor) or a fuel injector, its loss will cause the engine to run poorly or not start, triggering misfire and communication codes.

Q: How do I know which component is causing the fuse to blow? A: The process of elimination is your best tool. Find the fuse diagram to see what's on that circuit. Then, with the fuse out, disconnect the components on that circuit one by one (starting with the easiest to access) while checking for a short with a multimeter. When the short disappears, you've found your culprit.

Q: Is it safe to keep replacing the blown fuse until I find the problem? A: It's not recommended. Each time the fuse blows, it's because excessive current is flowing, which can heat and damage wiring. Replace the fuse only for diagnostic testing (to see what stops working) and immediately remove it once you've noted the symptom.

Q: My clutch interlock switch is often mentioned. What does it do? A: It's a safety switch that prevents the starter from engaging unless the clutch pedal is fully depressed. It sees constant mechanical movement and is prone to failure, often shorting out internally and blowing the starter fuse.

Source Summary: This analysis is based on 105 owner discussions from Reddit and automotive forums.