Mercedes-Benz AC Compressor Fuse Location (By Model)

On most Mercedes-Benz models, the AC compressor fuse sits in the engine-compartment fuse box, usually near the battery or under a labeled plastic cover, and it often shares a circuit with related systems. The exact fuse number and amperage are not the same across the lineup, so the most reliable answer for your car comes from the fuse diagram printed on the fuse-box lid or in your owner’s manual. Below we explain how the AC circuit is fused, how to find the right fuse safely, and when to suspect a relay instead.

Mercedes-Benz AC Compressor Fuse Location (Why It Varies by Model)

Mercedes-Benz has built many platforms over the years, and the AC fuse layout differs between them. A C-Class (W204/W205), E-Class (W211/W212), and M/ML-Class (W164) do not use identical fuse positions, and the same model can change between facelifts and model years. That is why you should never assume one fixed “fuse number” from a generic article.

That said, the AC compressor circuit on most Mercedes-Benz vehicles is protected in one of these places:

• Engine-compartment fuse box — the primary location for higher-current items like the AC compressor clutch and condenser fan. Look near the battery or along the firewall, under a clip-off cover.
• Interior fuse box — often in the driver’s footwell, behind a dashboard panel, or in the trunk on some models. This box may feed control circuits tied to the climate system.
• Relay or fuse/relay carrier — the compressor clutch is switched by a relay, which can sit in either box.

To find the exact fuse for your car, open the fuse-box lid and read the diagram molded or printed on the inside of the cover. Mercedes typically prints a legend that maps each numbered slot to its circuit. If the cover legend is worn off, the fuse chart in the owner’s manual lists every position, amperage, and the system it protects. On many models a small puller tool is clipped inside the box.

A note on shared 7.5-amp circuits

On some Mercedes-Benz models, a small fuse (for example a 7.5-amp fuse) feeds a control circuit that the AC shares with another system. Owners on Mercedes forums have traced AC faults to one of these shared low-amperage fuses. This is model-specific, though — confirm the amperage and slot against your own diagram rather than copying a number from another car.

How to Check the AC Compressor Fuse Safely

You can inspect fuses yourself without special skills. Work through these steps in order:

1. Turn the car off and remove the key. Let the engine cool before reaching into the engine bay.
2. Open the correct fuse box and read the cover diagram. Identify the slot labeled for the AC, climate control, or compressor clutch.
3. Pull the fuse straight out with the clip tool and hold it up to the light. A blown fuse shows a broken metal strip or scorching inside the plastic.
4. Replace it with the exact same amperage. Never fit a higher-rated fuse — that defeats the protection and can damage wiring.
5. If the new fuse blows again, stop. A repeat failure points to a short or a failing component, and that needs a technician.

If the fuse is fine, the next suspect is the AC compressor relay. The relay acts as a switch that energizes the compressor clutch; when it fails, the compressor never engages even though the fuse is good. Relays can be swapped with an identical one from a non-critical circuit to test, but diagnosing the compressor, pressure switches, or refrigerant charge is best left to a professional with the right gauges.

Frequently Asked Questions

What is the exact AC compressor fuse number on a Mercedes-Benz?

There is no single number that applies to every Mercedes. The position and amperage depend on your specific model, chassis code, and year. Read the diagram on the fuse-box cover or the chart in your owner’s manual to find the correct slot for your car.

How do I know if it’s the fuse or the relay?

Check the fuse first because it’s quick and free. If the fuse is intact but the compressor still won’t engage, suspect the relay or a sensor in the AC circuit. A repeatedly blowing fuse means there’s a deeper electrical fault, not just a worn-out fuse.

Where can I get a model-specific fuse diagram?

Your owner’s manual is the authoritative source. Mercedes owner communities such as MBWorld and BenzWorld are also useful for matching a fuse position to your exact chassis when the printed legend is missing or unclear.

Other reasons a Mercedes AC won’t blow cold

A blown fuse is only one possibility. If the fuse and relay both check out, the most common remaining causes on a Mercedes-Benz are a low refrigerant charge from a slow leak, a failed AC compressor or its clutch, a faulty pressure sensor that prevents the compressor from engaging, or a clogged cabin air filter that chokes airflow at the vents. Refrigerant and compressor work requires recovery equipment and is not a DIY job — that’s where a qualified technician comes in. A cabin filter, on the other hand, is an easy owner-level swap and worth checking if airflow is weak but the air is still cool.

Get the AC Working Again

Start with the engine-compartment fuse box, confirm the slot against your own fuse diagram, and replace any blown fuse with the same amperage. If the AC still won’t cool after a good fuse and a working relay, the issue lies deeper in the system — have a qualified technician check the compressor and refrigerant charge before you spend money on parts.