2006-2014 Subaru Legacy & Outback Fuse Box: A Guide to the Two Different Designs

Generation Split: Which Fuse Box Does Your Subaru Have?

The most important thing to understand when shopping for a main fuse box for a 2006-2014 Subaru Legacy or Subaru Outback is that two different, non-interchangeable designs were used. The model year 2010 was a complete redesign for both vehicles, and the fuse box changed with it. Using the wrong generation of fuse box will not work.

Symptoms of a Failing Fuse Box

A failing main fuse box often creates confusing electrical problems that can be mistaken for other issues. Because it's a central hub, its failure can cause multiple, seemingly unrelated systems to stop working at once.

• Multiple Electrical Failures: You may experience a combination of issues like the radio not working, power windows failing, headlights being inoperative, and the car not starting. If several unrelated electrical items fail simultaneously, the fuse box is a primary suspect.
• Engine No-Crank or No-Start: The fuse box houses relays and fuses critical for the starter and fuel pump. A failure within the box can prevent the engine from cranking or starting, even with a good battery.
🎬 Watch: Quick fix for a no-crank, no-start issue.
• Visible Damage, Corrosion, or Melting: A physical inspection may reveal obvious problems. Look for a white or greenish powder (corrosion) on the terminals, melted plastic around fuse or relay sockets, or a burnt smell. This is often caused by water intrusion or a loose connection causing high resistance and heat.
• Repeatedly Blowing Fuses: While a single blown fuse is common, if a new fuse blows immediately or repeatedly, it can indicate a short in the wiring or a problem within the fuse box itself, such as internal corrosion creating a short circuit.
• Buzzing or Hissing Noises: Any unusual noises coming from the fuse box area can indicate electrical arcing due to a poor connection, which is a serious fire hazard.

Known Issues, Recalls, and Service Bulletins

While the fuse box assembly itself has not been the subject of many direct recalls, related electrical issues and TSBs can lead to its failure.

Recalls

• Secondary Air Injection Pump Relay (Recall WTM-73): This recall affects some 2007-2009 Legacy and Outback models with turbocharged engines. A faulty relay, located in the main fuse box, could fail and cause the air pump to run continuously. This could overheat the pump, potentially melting it and increasing the risk of a fire. The fix involves replacing the relay.
🎬 See how to test and replace an air pump relay.
• Puddle Lights (Recall WQE-41): Affecting some 2010-2011 Legacy and Outback vehicles, this recall addresses an issue where optional puddle lights could short circuit when exposed to salt water, posing a fire risk. The fix involves installing an in-line fuse, highlighting how external electrical issues can relate back to the vehicle's fused circuits.
• Electronic Parking Brake (Recall WTV-81): On 2010-2014 Legacy and Outback models with manual transmissions, a defect in the electronic parking brake control unit could prevent the brake from engaging properly. While not a fuse box issue, it is a significant electrical system recall for this generation.

Technical Service Bulletins (TSBs) for Water Leaks

Water intrusion is a primary cause of fuse box and wiring harness corrosion. Several TSBs have been issued for water leaks that can lead to the kind of electrical problems that damage a fuse box.

• Sunroof Drain Leaks (TSB 12-117-10R): On 2010-2013 models, clogged or kinked sunroof drains can cause water to leak into the cabin, potentially affecting the interior fuse panel and related wiring.
• Cowl Area Leaks: A TSB was issued for water leaking into the passenger footwell area from a poorly sealed body seam in the cowl area, which can saturate wiring connectors.
• Vapor Barrier Leaks: TSBs exist for later models describing how water can enter the cabin through improperly sealed door vapor barriers, leading to corrosion in the footwell wiring connectors.

Buying a Used Main Fuse Box: What to Look For

A used OEM fuse box is an excellent, cost-effective alternative to a new part, which may be expensive or discontinued. Here’s how to inspect a used unit:

1. Verify the Part Number: This is the most critical step. Match the part number exactly or confirm it's a valid superseded number for your vehicle's specific generation (2006-2009 or 2010-2014).
2. Inspect All Terminals and Pins: Carefully check every pin and socket, both on top where the fuses/relays plug in and on the bottom where the wiring harnesses connect. Look for any signs of green or white corrosion, water marks, or rust. Reject any unit that isn't perfectly clean.
3. Check for Heat Damage: Look closely at the plastic around each fuse and relay socket. Any signs of melting, warping, or discoloration indicate a previous circuit overload or a poor connection that created excessive heat.
4. Examine the Casing: Ensure the plastic housing is not cracked or broken, especially around the mounting tabs and connector latches. A damaged case can allow moisture and dirt to enter.
5. Ask About the Donor Vehicle: If possible, find out the mileage and history of the vehicle the part came from. A low-mileage part from a vehicle in a dry climate is always preferable.

Cost of Replacement

The cost to replace the main fuse box can vary significantly based on the part source and labor rates.

Frequently Asked Questions (FAQ)