Turn on the ignition switch. Press down on the brake pedal. You will hear the pump running for the brakes. I believe this is what you are hearing. This pump runs when the engine dies to give you power steering and brakes. It is not supposed to run when the engine is running. Get back to us with your results and we will go from there.
1998 Pace Arrow 35 ft. F53 Ford V10 2012 Honda Civic toad
15 year motorhome service manager. 3 popups....2 travel trailers....5 motorhomes....loved them all.