I have a 1998 S70 and the heater only blows cold air (outside temp air), the cars temp gauge shows normal operating temperature and the fan works but the air coming out of the vents is cold. Any suggestions on what may be wrong?

 

The blend MIX vent is open. Close it and you'll be fine.

Welcome to the forum.

 

If that doesn't work, let me know and I'll go to option #2.

 

Thanks for the reply, After I posted this it started to work again, blend mix must be sticking when it extreamly cold.