Land Yacht 33 - Dash Vent or AC gets hot in slow traffic - do this
This one is a problem of inlet location.
in my 1995 Land Yacht with P30 Chassis the air inlet for the dash AC comes from directly above the passenger side tire. This gives two issues.
First on dirt roads etc - you get dust in your face with the vent going.
Second - When you stop moving, heat from the engine bay leaks out through the fenderwells as the fan pulls air through the radiator which then has no where to go.
I solved this problem by going to Home depot and picking up the vent top to a Hot Water Heater and a length of aluminum dryer duct tubing. I attached and sealed with RTV Sealant the vent top with screws into the bottom of the fenderwell. Next I attached the dryer tubing to the vent top with 4 sheet metal screws and then with Duct tape to make an airtight seal. Finally I fed the dryer ducting up and pointed it forward behind the grill so it gets fresh air.
I used a few Zipties to attach and hang the dryer tubing and a hoseclamp at the front to secure it behind the grill.
This cured the hot air from the dash issue with the added benefit of increased airflow from the vents while driving at freeway speeds.
Hope this helps.