2020 Mercedes-Benz Metris Fuse Box Diagram & Amperage

As an ASE-certified master technician, I know how frustrating electrical gremlins can be, especially on a modern European workhorse like the 2020 Mercedes-Benz Metris (W447 platform). Whether you have the Cargo or Passenger van, knowing exactly where to find your fuses and what they protect will save you hours of diagnostic time. Below is your comprehensive guide to the fuse boxes, amperages, and relay locations for the 2020 Mercedes-Benz Metris.

Disclaimer: Mercedes-Benz frequently updates electrical architectures based on trim level, upfitter packages, and exact build dates. Always verify fuse layouts with the printed paper legend folded up inside your specific vehicle’s fuse box lid.

Quick answer

On the 2020 Mercedes-Benz Metris, you will find three primary fuse box locations:

1. Under-hood (Engine Compartment Fuse Box): Located on the passenger side near the firewall, under a black plastic cover.
2. Passenger Footwell (Interior Kick-Panel Fuse Box): Located in the front passenger footwell area, behind the lower dashboard/kick-panel trim cover.
3. Under Passenger Seat (Auxiliary/Rear Fuse Box): Located underneath the front passenger seat base, accessible by sliding the seat forward or removing the side cover.

Engine Compartment Fuse Box

This fuse box manages the heavy-duty powertrain and chassis systems. Relays for the starter, Engine Control Module (ECM/PCM), and main ignition circuits are also located in this block.

Note: Relays for the Starter, Horn, and Engine Circuit 87 are integrated into the lower tier of this fuse module.

Passenger Footwell Fuse Box (Dash/Kick-Panel)

Located inside the cabin on the passenger side, this block manages most of your creature comforts, driver interface systems, and interior lighting.

Note: The primary interior relays, including the Circuit 15R (Accessory) relay and the rear window defroster relay, are mounted adjacent to this fuse block.

Under Passenger Seat Fuse Box (Auxiliary)

Because the Metris is often used as a commercial vehicle or camper conversion, Mercedes routes many of the body, cargo, trailer, and upfitter power feeds to the fuse block located under the front passenger seat.

How to test a fuse

When an electrical component stops working, testing the fuse is always step one. Don't rely solely on pulling the fuse and looking at it—micro-fractures in the fuse filament can look intact to the naked eye but still disrupt the circuit.

1. Use a 12V Test Light: Turn the vehicle ignition to the "ON" position (do not start the engine). Attach the test light's ground clip to a bare metal surface on the chassis. Touch the probe to the small exposed metal testing tabs on the top of the fuse. If the test light illuminates on one side but not the other, the fuse is blown.
2. Use a Digital Multimeter: Set your multimeter to the continuity setting (the one that beeps). Touch one probe to each of the two metal testing tabs on the top of the fuse. A continuous beep means the fuse is good. No beep means the circuit is broken, and the fuse needs replacement.
3. Always replace like for like: Never replace a blown fuse with one of a higher amperage. This can cause the vehicle’s wiring harness to overheat, potentially leading to a catastrophic electrical fire.

Common blown fuses on this vehicle

Based on my time in the service bay, here are the most common fuses that blow on the 2020 Mercedes-Benz Metris and what to check first:

• 12V Power Outlet / Cigar Lighter (Fuse F48): Commercial drivers plug in a lot of accessories—phones, tablets, dash cams, and heavy-duty inverters. If your outlet goes dead, check this 15A fuse in the passenger footwell. If it blows repeatedly, inspect the 12V socket itself for dropped change or debris shorting out the contacts.
• Trailer Lighting (Fuses F110 / F112): The Metris makes a great light towing rig. However, poorly wired trailers are notorious for causing shorts. If you lose your trailer lights, check the fuses under the passenger seat. Always inspect the trailer wiring harness for frayed wires before hooking it back up.
• HVAC Blower Motor (Fuse F45): If you completely lose air coming from your vents, this 40A maxi-fuse in the passenger footwell may be the culprit. If the fuse is good but the blower only works on the highest setting, your blower motor resistor has likely failed.

If you’ve replaced a fuse and it immediately blows again, stop. You have an active short circuit that needs to be diagnosed by a professional to avoid damaging expensive control modules.

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