Just got a '98 F150 and the A/c blows HOT !! It seems that even with A/C on the airflow is still beiong directed across the heater core. With A/C on, I have a cold tube coming out of the silver cylinder up against passenger side firewall. [Receiver/Dryer ??], so I suspect the R-134a charge is at least enough to cool some. Plan on checking the charge tonight and re-chargeing if necessary, anyone else have suggestions ??

 

check the switch to be sure it is actually switching between heat and A/C if thats the case be sure the vacum is moving the airflow from the heater core to the evap to provide cold A/C....an easy way to see if the A/C is running is to switch to MAX and watch the compressor to see if it is running. Im sure there are others on here who have some advice as well but id check the obvious things before you blow up a compressor by overfilling it.....oh yea PS those R134a cans with the gauge on them are WRONG i almost blew up the compressor on my G/F's Honda CR-V it was putting out like 370psi on high side which is critical.....if you dont have REAL gauges dont do it.

 

Thanks. I strongly suspected the airflow was not being switched. I am going to check it out tonight or tomorrow and I will let you know the outcome.

 

good deal man let us know what it is just in case we have the same trouble in the future