Originally Posted by sides

Hi all,

Cruising down the highway two nights ago, suddenly the heat stopped working in my 300d. It just started blowing cold air. Interestingly, before it stopped, when the heat did work, it only blew out of one of the air vents. When it stopped and only blew cold air, it blew it hard out of all the air vents.

I've been reading here about the monovalve. Where is it and is that the problem? Any other ideas are greatly appreciated. It's getting cold.

Many thanks,
BS