Vincent The Dragon

Okay...so here is the thing...it's friggen hot outside. AC in the truck is usefull.

Problem...it blows hot air, or on max AC only kinda blows cool.

It's something I have been putting off for a while to fix.
I tried adding refrigerant but that did not help. The AC system all seems to be working fine.
I replaced the temperature selection switch..no go..

Some internet research .. common problem.
Cause..the plenum blend door. Aparently it breaks..Why? It made of plastic and not well constructed.
Whats is it?...well...the plenum is the big plastic thing your air vents all run too, there is a heater core and an AC core in it. The blend door opens and closes the space between the AC and the heater core.

How to fix it...well...the small plenum assy is like $400 or more from Ford and to remove it you have to pull the heater core (not to bad) and the AC core (requires special tools and removing all the refrigerant from the system) AND pulling the entire dash board out...bad!!!!

okay..so..you can buy a nice replacement that will never fail for $120 and to replace it..you stand on your head and drimel out the bottom of the plenum; put the new on in and glue the plenum back together.

Sooo..i drimeled out the bottom of the plenum (yes, there is now a large hole under the dash of my truck). I epoxied the broken piece back on the door and when its dry, I will drill a hole and cut a ridge for a nice metal band so this part never breaks again. Slide the unit up into place and fit the bottom of the plenum back into place, Once I know the movement of the door works nicely I will back fill the cut out piece with epoxy and it should last forever.

Cars are NOT efficient machines, A heater core gets hot even if the single valve it uses is closed because the other side still has engine coolant. Even if there were two valves it would get hot through the valve. A better way, I think, is to not have a heater core at all and just use an electric ceramic heater that would positively be off unless needed....less moving parts, better heat/cool control...Stupid car engineers...