Blower works erratically (for both hot & cold)

Why doesn’t the blower work in my 1995 car when:



1. The air conditioner worked fine on trip of an hour and a half.

2. On the return trip perhaps 8 hours later, I tried the air conditioner and the heater and the defroster but no go: the fan makes noise (I can hear it and adjust the supposed speed), but NOTHING comes out of the blower (hot or cold) . . . until about an hour and a half later.

3. This did NOT happen when I made an even longer trip and only used the heater - which worked fine both ways.

It sounds like the door for the vent system is having trouble. This may be controlled by vacuum air and there could be a problem with that. Some systems are controlled electrically.

Thanks. Do you know how it can be repaired? Or does the whole blower have to be replaced?

You stated that the blower motor works so that should be ok. The vent doors are harder to work on as they are inside the ducting system. You should let someone at a good shop have a look at it see what they say. It may be as simple as just a bad connection to the vent door motor or it is just stuck.