Experiencing a problem with my OTR heat/air on my way from Iowa to Florida. After 3 days of fog, rain, and road grime, the passenger heat/air unit would shut off seemingly when pulling off interstate and driving slowly or ready to stop. It would not turn back on pushing the on/off button for 30-60 seconds. Is something overheating and thus shutting down? Are there filters under the bus that have gotten dirty creating this problem? I.m all ears.thanks!!