Been quite sometime since I have run the heater in my 1999 V10 F250. This morning it was a little brisk and I went to turn in on and no hot air blowing out. Just felt like the vent was on. The fan is blowing air just fine but can't get any heat to come out of it. Anyone had this problem before? I have no idea what to look for and needed some advise on where maybe to start. Maybe a bad valve or vacuum hose somewhere. I looked inside and out and couldn't even locate a heater control valve. I don't know. Any help would be greatly appreciated.

Thanks,

Mike

 

My brother had that happen on his ram, and it was cause the heater core was plugged up. Could also be low coolant or a bubble since the heater core is usually the highest point in the system.

 

Check the operation of your blend door.