1999 F-150 XLT 4X4 No Heat
 

1999 F-150 XLT 4X4 No Heat
 

No Heat when heat turned on. Engine running normal in Temperature Range What's up?:-X25 :'( :-X01

1999 F-150 XLT 4X4 No Heat
 

[updated:LAST EDITED ON 27-Sep-02 AT 10:16 AM (EST)]Check your Gate valve out by the Fire wall. It's inline with one of the Heater hoses. Or the Dash control unit has something wrong.
It sounds like your gate valve is not opening to let the hot antifreeze in to the heater core.

1999 F-150 XLT 4X4 No Heat
 

[updated:LAST EDITED ON 27-Sep-02 AT 10:54 AM (EST)]Verify that the coolant level is ok as well. The temp guage may not signal an insufficient quantity of coolant in cooler weather. I would also consider a cooling system flush in the future if a stuck valve is the cause.

1999 F-150 XLT 4X4 No Heat
 

This same problem just started with my 1999 F-150 today. I just found this website today search for answers to this problem. Good info. Thanks guys helped me a lot.

1999 F-150 XLT 4X4 No Heat
 

I had a truck that had a bad temp control knob. I pulled the temp control knob off and turned it with plyers, ah heat. Replaced knob problem solved. The old knob had a small crack that would let the knob slip on the shaft and not turn on the heat.:D

1999 F-150 XLT 4X4 No Heat
 

Being from Ohio myself, I've experianced this problem before as well. Cut a piece of cardboard big enough to cover most of the radiator. Then shove it down in front of the radiator to block the wind from hitting the radiator. Works like a champ. Of course, you only want to do this if it is real cold out.

No Heat? Check this first...
 

The newer f150s don't have a valve in the heater hose to control the heat. Heat is controlled by an air damper in the heater box. The damper is controlled by a small servo motor unit on the bottom of the box and the position of the servo is controlled by the variable resistor connected to the temperature control knob on the dash. If you don't have heat, check the servo motor first. It's easy to get to and easy to replace.