1991 Aerostar. Heater fan control.

[GrandpaDan]

My heater fan runs fine with the control on Vent, but when I set it on heat or defrost, the fan shuts off. Move the control back to vent, fan goes on.
Any suggestions?

 

[don-ohio]

My heater fan runs fine with the control on Vent, but when I set it on heat or defrost, the fan shuts off. Move the control back to vent, fan goes on.
Any suggestions?

Might just be a bad switch.It happens............. replace it. don-ohio ^)

 

[BrooklynBay]

Does this happen when you set the fan on a low speed or at any speed?

 

[GrandpaDan]

Does this happen when you set the fan on a low speed or at any speed?

The fan has its full range of speeds with the temperature control on vent, but change it to heat or defrost and it shuts off.

 

[don-ohio]

Yes,selector switch may be bad. don-ohio