Posted 5/23/2022 07:23 (#9671793 - in reply to #9671487) Subject: RE: MT875c hot and loud cab
The duct running under the floor for the dash vents is not insulated. Keep them shut and run the ac all through the rear ducts. Putting a valve in one of the heater lines is a requirement. There is a handy spot right in front and below the cab.