My wife and I recently purchased a conversion van and the heat works, however, when the van is in motion, cold air vents on the driver's and passenger's feet. When stopped, your feet are warm, otherwise no. The passenger side is intermittent but the driver's side is constant. Any ideas?

 

vaccuum leak somewhere.

 

Probably an air leak down there blowing on your feet when moving, possibly the doghouse seal.

 

my 1994 has a fresh air vent on the driver side kick panel. it slides to open/close. on mine, I have to push in a bit to slide it.

you may wanna grab a flashlight and look around down there for a fresh air vent

also, along with a doghouse seal, your doors' weathersealing may have gaps and need replacing.

 

Thanks daguvena, you were dead on, air vent.

 

I have about 40% of the radiator blocked with a thin piece of wood paneling to keep the engine warm for the winter. From 1998 to 2003, the front area is different than previous years, thus placing the panel up against the radiator works.