2015 Freightliner M2 106 – Fuse Box Diagram & Amperage

Quick Answer

The 2015 Freightliner M2 106 typically has two main fuse box locations: the under-hood fuse box (often referred to as the Power Distribution Module or PDM) and the in-cab fuse box (located on the driver's side kick panel). Some configurations might have an additional fuse panel for body builder circuits or specific accessories, but these two are the primary locations.

Under-Hood Fuse Box (Power Distribution Module - PDM)

This fuse box is generally located on the driver's side under the hood, near the firewall. It houses fuses and relays for critical engine and vehicle systems.

Relay Locations (Under-Hood):

• R1: Starter Relay
• R2: Fuel Pump Relay
• R3: Headlight Low Beam Relay
• R4: Headlight High Beam Relay
• R5: Blower Motor Relay
• R6: A/C Clutch Relay
• R7: ECM Main Relay

In-Cab Fuse Box (Driver's Side Kick Panel)

This fuse box is typically located on the driver's side, often behind a removable panel on the kick panel area. It contains fuses for various interior accessories and controls.

Relay Locations (In-Cab):

• R1: Accessory Relay
• R2: Power Window Relay
• R3: HVAC Blower Relay (Low Speed)

Note: Fuse box configurations can vary slightly between different trim levels and specific options installed on your 2015 Freightliner M2 106. Always refer to the printed legend on the inside of your fuse box cover for the most accurate and up-to-date information for your specific vehicle.

How to Test a Fuse

Testing a fuse is a straightforward process:

1. Safety First: Ensure the ignition is off before handling fuses.
2. Locate the Fuse: Remove the fuse box cover and identify the suspicious fuse based on your vehicle's symptoms and the fuse box diagram.
3. Visual Inspection: Most modern fuses have a clear plastic body. Look for a broken wire or blackened area inside the fuse. If you see a break, the fuse is blown.
4. Using a Multimeter (for a more accurate test):
   • Set your multimeter to the continuity setting (often indicated by a speaker icon) or the ohms setting.
   • Touch the probes to the metal contact points on the top of the fuse (or remove the fuse and touch the probes to each end).
   • A good fuse will show continuity (the multimeter will beep or show a very low resistance reading). A blown fuse will show no continuity or an "OL" (open circuit) reading.
5. Replace if Blown: If the fuse is blown, replace it with a new fuse of the exact same amperage (AMP) rating and physical size. Using a fuse with a higher amperage can lead to serious electrical damage or fire.

Common Blown Fuses on This Vehicle

While any fuse can blow, some are more commonly affected due to their circuits or usage:

• Cigar Lighter / 12V Power Outlets: These fuses often blow due to short circuits from faulty accessories plugged into them or from exceeding the circuit's amperage limit.
  • What to check first: Disconnect all accessories from the outlets before replacing the fuse. If it blows again immediately, there might be a wiring issue in the outlet itself.
• Headlight Fuses: A blown headlight fuse can result in one or both headlights failing. This can sometimes be caused by a faulty bulb or an intermittent short in the wiring.
  • What to check first: Inspect the headlight bulbs. If a new fuse blows with new bulbs, inspect the wiring for any signs of chafing or damage.
• Blower Motor Fuse: If your HVAC fan stops working entirely, the blower motor fuse is a common culprit, especially if the blower motor has been straining.
  • What to check first: Listen for any unusual noises from the blower motor. If the fuse blows repeatedly, the blower motor itself might be failing.
• Trailer Brake Controller Power Fuse: Frequent use or a short in trailer wiring can lead to this fuse blowing.
  • What to check first: Thoroughly inspect the trailer's wiring and the connection to the truck for any shorts or damage before replacing the fuse.
• Radio / Infotainment Fuse: If your radio suddenly goes dead, this fuse is a prime suspect. It can blow due to internal radio faults or wiring issues.
  • What to check first: Try resetting the radio if possible. If the fuse blows repeatedly, there may be an issue with the radio unit or its wiring.

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