1997 Ford F250 V8 Four Wheel Drive Manual 120000 miles
I have tried everything, new heater core, tore apart the dash and all valves are working ok(heating and cooling vents) great air flow, when you reach up in the box it is very warm. You get more heat when its on vent than when on heater. Any ideas?
Did you replace the thermostat and also check for a heater control valve that's malfunctioning
September, 30, 2008 AT 11:51 AM
Yep I did, can't find any valves that are malfunctioning, they all seem to open and close right.
September, 30, 2008 AT 12:07 PM
Is there a valve attached to the heater hose before it enters the heater core
September, 30, 2008 AT 12:21 PM
Nope just straight in, its hot going in and out of the heater core
November, 21, 2008 AT 11:10 AM
Did anybody figure this one out? I am having the exact same problem with a 97 F 250. Thanks in advance.
January, 29, 2010 AT 12:44 PM
I had same problem. Replaced thermostat and heater core. Here's all it was. An ink pen.
Take the glove box door off to see the blend door cable. Make sure it appears to be working. Then remove the heater core cover and blend door cable.( I had to loosen up the dash to get the cover out.) Now look inside the plenum and manually move the blend control door from hot to cold. If it doesn't go completely to the left closing off the plenum then you may have a pen or something out of view on the floor of the plenum. Take a wire or hook shape tool and rake it along the bottom next to the door and listen for anything loose.I was able to squeeze my hand in enough to remove it. Check door again and it should go completely closed.