drivepirate
Member
Hi all. I had the common defrost default issue that many people have experienced. After reading through the forums I had some ideas about the issue. My particular solution was not discussed so I thought I would share.
My Expedition has a purely electric environmental control head so no o rings to replace. Next I looked under the hood on the passenger side near the firewall. There are a bunch of vacuum lines that split and snake all over the place. Mine had some short sections that were severely corroded and one was even broken. I replaced everything with some old fuel line I had and BAM! Back in business.
So if you cannot change air flow to the floor or vent, check the vacuum lines from the manifold to the check valves and finally to the retention tank (plastic box aka what the hell is this for?).
My Expedition has a purely electric environmental control head so no o rings to replace. Next I looked under the hood on the passenger side near the firewall. There are a bunch of vacuum lines that split and snake all over the place. Mine had some short sections that were severely corroded and one was even broken. I replaced everything with some old fuel line I had and BAM! Back in business.
So if you cannot change air flow to the floor or vent, check the vacuum lines from the manifold to the check valves and finally to the retention tank (plastic box aka what the hell is this for?).
