Roadmaster air vent stinks--where is intake
 

Have a Roadmaster and love it :), but last 2 weeks interior air vents stink of dead (bird? fish? mouse?) anytime I turn blower on.:( Checked air filter intake, screened intakes at base of windshield--no debris. Sprayed deodorizer into both, can smell it and vent still stinks.

Is there another outside air intake somewhere?