91498-348 | Genuine Trico® WIPER MOTOR

1. Primary Commercial Vehicle Platforms

Trico 91498-series wiper motors are factory standard equipment or heavy-duty service replacements for Class 7 and Class 8 North American commercial trucks and transit buses. This specific unit is widely mapped to:

• Freightliner Trucks: Select model years of the Freightliner M2 (2001-up business class) and Freightliner Cascadia.

• International Trucks (Navistar): Multi-purpose medium/heavy-duty applications, including the International ProStar, LoneStar, DuraStar (4000 series), and WorkStar (7000 series).

• Commercial Transit Buses: School and municipal buses built on International 3200 chassis platforms.

2. Mechanical Interface Note

The 91498-348 features a specific mechanical shaft spline, mounting plate pattern, and a 12-Volt wiring plug layout designed to interface with the factory wiring loom without wire splicing.

1. What is it?

Produced by Trico®—a global pioneer in windshield wiping technology for over a century—this part acts as the primary power source for clearing rain, snow, and road debris from wide-area commercial windshields. The "91498" designation belongs to Trico's heavy-duty platform family, built specifically to handle the friction of extra-long wiper blades under severe weather conditions.

2. Core Functions

• Rotational-to-Linear Force: The internal 12-Volt electric motor spins at high speed, while an attached mechanical gear reduction box converts that speed into low-RPM, high-torque output to sweep heavy commercial wiper linkages.

• Multi-Speed Regulation: It relies on an internal circuit system to smoothly alter electrical current, giving the operator access to intermittent, low-speed, and high-speed operational cycles.

• Automatic Parking Contact: The motor integrates a specialized electrical contact plate (the "J1" or parking circuit). This ensures that when the operator switches the wipers off, the motor continues running just long enough to safely park the wiper blades flat at the absolute bottom base of the windshield glass.

1. Wipers Stop Randomly in the Middle of the Windshield ("Park" Failure)

The "J1" designation in this Trico motor signifies an integrated automatic parking circuit. When this internal electrical contact plate wears down, burns out, or loses tension, the wipers will immediately freeze wherever they are the exact second you turn off the wiper switch—leaving the blades directly in the driver’s line of sight instead of parking flat at the bottom of the glass.

2. Complete Failure on Specific Speed Settings

Heavy-duty Trico motors use independent internal brush contacts to regulate speeds. If the wiper blades work perfectly on "High" but completely die or lock up when switched to "Low" or "Intermittent" (or vice versa), the internal speed control circuits within the motor casing have failed.

3. Extremely Slow, Hesitant, or Erratic Operation

If the wiper blades crawl slowly across the glass, judder, or periodically freeze before forcing themselves forward, the motor's internal electrical armature windings are likely short-circuiting, or the magnets have degraded.

Diagnostic Note: Ensure your wiper linkage (transmission) mechanical joints are greased; if the linkage is free but movement is still weak, the Trico motor is failing.

4. Loud Humming or Buzzing Noise with No Movement

Turning the wiper switch to the "On" position results in a distinct electrical hum or buzzing sound from the firewall/bulkhead area, but the wiper arms do not move. This indicates that the electric motor is getting power, but the internal plastic/composite gear reduction wheel inside the Trico assembly has stripped out or the main output drive shaft has completely seized.