New member Heater HELP NEEDED!

[kiber71]

I have an 03 Explorer Limited, just hit 100K miles seems have been having little probs off an on. NEWEST is I start truck warm up climate control USED to NOT kick out anything until was warm enough to blow heat. Now it almost instantly blows COLD AIR that is until I start driving. When I stop for more than 30 seconds, it blows cold air again. I tried giving it gas in park and get warm air. We changed the Thermostat today, old one looked fine, and NO change. I was low on Anti-freeze, filled it back up, but still NO change!
I'm STRESSED!!
Thanks!
Kimmie

 

[cjones101812]

try disconnecting the Heater Control Valve vacuum connector and plug connector.