[rnln]

Don't laugh at me for asking this question. I have this car for many years but I never can get the heater to work with fan on.
When I pull on the red levers at the mid console, I do get good amount of heat, and usually that's all I need.

Occasionally I want more because it's so cold, I try to turn on the fan (controls are at the front dash, above the shifter), then immediately, no more heat.

Another reason to turn on the fan is when my front windshield is foggy, I turn on the fan to blow it up on the windshield to defrost it, then my heater won't release hot air any more.

Another occation is when the car is iddling, or driving too slow around town while it's too cold outside (our car need higher RPM for the heater to blow hot air, even the red levers are all the way up), then I want to turn on the fan so it can blow hot air to my hands. Soon the fan is on, the air won't be cold anymore, even at the kick panel vents.

Why? Is this the way our car built?