The Freightliner FL80 (part of the Business Class series) was a medium-duty truck built for durability. Unlike modern trucks that use standardized, digitally-mapped fuse blocks, the 1994 model sits at a crossroads. It features a mix of old-school blade fuses (ATO/ATC), maxi-fuses for high-current circuits, and a few circuit breakers for critical safety systems.
Crucial Note: In 1994, Freightliner was transitioning between wiring harness suppliers. Some FL80s have a single fuse panel under the dash; others have a primary fuse box under the hood plus a secondary relay panel. Your exact 1994 Freightliner FL80 fuse box diagram may vary based on: 1994 freightliner fl80 fuse box diagram
While wire colors and positions could be custom-ordered, a standard 1994 FL80 cab fuse block generally follows this pattern (standard ISO relay logic applies to the relays): The Freightliner FL80 (part of the Business Class
| Fuse Position (Typical) | Amperage | Circuit Protected | | :--- | :--- | :--- | | F1 | 10A | Instrument Cluster / Gauges | | F2 | 15A | Turn Signals (Left & Right) | | F3 | 20A | Horn / Cigarette Lighter | | F4 | 15A | Backup Lights | | F5 | 15A | Stop Lights / Brake Lights | | F6 | 20A | Heater Blower Motor / AC | | F7 | 10A | Parking Lights / Dash Illumination | | F8 | 20A | Headlights (Low Beam) | | F9 | 20A | Headlights (High Beam) | | F10 | 15A | Dome Light / Courtesy Light | | F11 | 10A | Radio / Stereo | | F12 | 15A | Wipers / Washer Pump | | SPARE | Various | Spare Fuses | This often handles the radio memory, auxiliary power
For trucks with a sleeper cab or extensive auxiliary packages, a third, smaller fuse block may be located behind a removable kick panel on the passenger side or behind the glove box. This often handles the radio memory, auxiliary power ports, and sleeper lights.
Solution: Fuse #9 (15A clearance lights) is likely blown. But this is a symptom of a chafed wire behind the front bumper or along the frame rail where the harness rubs.