Stay powered up, and keep that classic FL80 rolling.

Freightliner FL80 Fuse Box Diagrams & Locations - JustAnswer

Check the wiper/washer fuse (usually 20A).

To give you an idea of what you're looking for, here is a fuse chart from a 1998 Freightliner Cargo manual. Use this only as a reference —yours may be different. Always try to find the diagram specific to your truck.

| Fuse № | Amperage | Circuit/Component Protected | Relay № | Circuit/Component | | :--- | :--- | :--- | :--- | :--- | | 1 | 5A | Instrument Panel Lights | 1 | Heater/Air Conditioner | | 2 | 15A | Horn / Headlight Dimmer | 2 | Brake Lights | | 3 | 20A | Ignition Power | 3 | Accessory Power (Ignition Switched) | | 4 | 15A | Radio / Cigarette Lighter | 4 | Horn | | 5 | — | Not Used | 5 | Ignition Switch | | 6 | 20A | Tail / Marker / License Lights | 6 | Accessory Power (Battery Direct) | | 7 | 20A | Gauges / Indicator Lights | 7 | Parking Brake Warning | | 8 | 25A | Heater Blower Motor | | |

A single misplaced fuse can cripple your truck. The 1994 FL80 does not have the fully computerized diagnostics of modern trucks; it relies on a series of blade fuses, maxi-fuses, and circuit breakers. Using an incorrect diagram can lead to:

: Inline fuses and high-amperage fusible links are also located in the engine compartment near the starting batteries and fire wall. Understanding Freightliner Wire Numbering

Check fuse #15 (5A ECM ignition feed) in the interior panel AND fuse F6 (30A) in the PDC. Also, verify the ECM relay clicks when the key is turned to “ON.” These fuses are notorious for corrosion because the PDC sits near battery acid spray.