2017-2021 Jeep Compass Fuse and Relay Center: Solving Electrical Glitches and No-Start Issues

Symptoms of a Failing Fuse and Relay Center

Failure of the Fuse and Relay Center itself is less common than individual fuses or relays failing. Most electrical problems, like a no-start condition or malfunctioning accessories, are more often caused by a weak battery, a bad alternator, or a faulty ground connection. However, when the fuse box assembly does fail, it can create confusing and widespread issues. Symptoms are often caused by internal corrosion, cracked circuit paths, or heat damage from a poor connection.

• Multiple Unrelated Electrical Failures: You might experience several electrical systems failing at once, such as the radio, power windows, and interior lights all acting up.
• Intermittent Power Loss: Circuits may work one moment and fail the next. This can be due to a loose internal connection or corrosion affecting conductivity.
• Engine Will Not Crank or Start: If the internal circuits that power the fuel pump relay or starter relay are compromised, the engine may not start, even with a good battery. You might hear a click, or nothing at all.
• Visible Damage: The most definitive sign of failure is physical evidence. This includes melted plastic around a fuse or relay socket, significant green or white corrosion on the terminals, or cracks in the housing.
• Persistent Battery Drain: A short circuit within the fuse box can cause a continuous power draw that drains the battery, even when the vehicle is off.

Associated OBD-II Codes

A failing Fuse and Relay Center will not typically set a trouble code that names the box itself (e.g., "Bad Power Distribution Center"). Instead, it will cause codes related to the circuits it powers. For example, if the internal connection to the fuel pump relay is bad, you might get a code for the fuel pump circuit. The key is to use the code as a starting point. If a code like P0600 (Serial Communication Link Malfunction) or a U-code (Network Communication) appears along with multiple other electrical faults, it could point to a problem with a central module like the fuse box. Diagnosis involves testing for power at the specific fuse or relay socket indicated by the trouble code.

Known Issues, Recalls, and Technical Service Bulletins (TSBs)

While there are no recalls specifically for the Fuse and Relay Center on the 2017-2021 Jeep Compass, there are related electrical system issues and recalls that are important to know.

• Recall U87 / NHTSA 18V-332: Some 2018 Compass models were recalled for a faulty Powertrain Control Module (PCM) that could cause the engine to stall or not start. This is often confused with a fuse box issue, but it involves a different electronic module.
• Recall T46 / NHTSA 17V-433: Early 2017 models came with an owner's manual that had incorrect instructions for jump-starting the vehicle. Following these instructions could reverse polarity and cause significant electrical damage, potentially harming the fuse box or other electronics.
• Water Intrusion: Some owners have reported water leaks into the vehicle, particularly around the cowl (the area at the base of the windshield) and in the rear cargo area. A clogged cowl drain can cause rainwater to overflow into the engine bay, potentially reaching the Fuse and Relay Center and leading to corrosion and failure.
🎬 See how to fix common floor water leaks in a Jeep
• Electrical TSBs: Jeep has issued several software updates for the Body Control Module (BCM) and other modules to address problems like intermittent warning lights and battery drain. It's wise to ensure your vehicle's software is up to date before replacing hardware like the fuse box.

Does This Part Need to Be Programmed?

No, the Fuse and Relay Center itself does not require any programming, flashing, or dealer intervention after installation. It is a non-intelligent part that simply holds and connects fuses and relays. You can swap it with a compatible replacement without needing special tools. This makes it a very DIY-friendly replacement.

The confusion often arises because other electronic modules in the vehicle, like the Powertrain Control Module (PCM) and Body Control Module (BCM), do require programming if they are replaced. However, for the fuse box assembly, the procedure is simply to disconnect the battery, unplug the connectors, unbolt the old unit, and install the new one.

Buying a Used 2017-2021 Jeep Compass Fuse and Relay Center

A used OEM fuse box is an excellent, cost-effective alternative to a new dealer part, especially since reliable aftermarket versions are generally not available. Here’s what to look for to ensure you get a good part.

1. Compatibility is Critical: Match Your Vehicle's Options

This is the most important step. Not all fuse boxes for the 2017-2021 Compass are the same. The internal wiring differs based on the vehicle's features. To ensure a perfect match, the donor vehicle must have the same:

• Engine: 2.4L
• Transmission: 6-speed Automatic
• Headlamps: Halogen Headlamps (not HID or LED)

Always match the OEM part number from your original unit to the replacement. The most common part number is 68343906AC.

2. Physical Inspection Checklist

When buying a used unit, a thorough visual inspection is key. Ask the seller for clear, high-resolution photos of these areas:

• Terminals and Sockets: Look inside every socket where a fuse or relay plugs in. There should be no signs of green or white crusty corrosion, or blackened/melted plastic.
• Main Connectors: Inspect the large electrical connectors on the bottom or sides. All pins should be straight, clean, and free of corrosion.
• Housing Integrity: Check for any cracks, especially around the mounting points. Ensure all plastic locking tabs for the cover and connectors are intact.
• Signs of Water Damage: Look for faint water lines or mineral deposits on the housing, which indicate it may have been exposed to moisture.

3. Why a Used OEM Part is the Best Choice

For a complex electrical part like this, a used OEM unit is often superior to a new aftermarket one (if you could even find one). The OEM part was designed specifically for your vehicle's wiring harness, ensuring perfect fitment of all connectors and mounting points. The materials used in OEM fuse boxes are designed to withstand the harsh under-hood environment of heat and vibration for many years.

Replacement Cost

The cost to replace a Fuse and Relay Center can vary significantly based on the part source and who performs the labor.

Frequently Asked Questions (FAQ)