faxtell

1985 Ford F150 with 302 I believe. Heater works good but will not blow air out the frost. Check the vacuum lines under the dash and a pod under the hood. Nothing seems to help. The A/C belt is off, but this shouldn't cause the fan to not switch to the defrost should it?

Any help would sure be appreciated.

Thanks

Just call me Sean

iTrader: (1)

The vent controls are vacuum operated. Defrost is the default setting, meaning if no vacuum is present defrost is what you get. That way if there's a problem you at least have defrost. Disconnect the vacuum supply that runs through the firewall from under the hood and see if it automatically goes to defrost. If it does then the selector switch is bad. If it doesn't then the door that moves to select the proper vent location is stuck or broken.