Rooftop AC Compressor works, fan blows low, even if on high

My Rooftop AC compressor is working and creating cold air, however, when I change my fan speed from low to high on the wall mount thermostat, the fan speed does not increase to high. Worked on high yesterday, however, for overnight we set to low. This morning, as it heats up, went to move it back to high and it continues to blow low only. Camper is heating up! What/where to look?

Thanks for the assistance,
-Chris

2004 Jayco 325BHS