Hey everybody. New member here. I'm having what seems to be an unusual issue with the A/C on my '05 XLT 4.0L. I only get hot air on anything but Max A/C. The blend door and actuator are working correctly, dropped the glove box and confirmed it visually. The coolant shut off valve for the heater core is working correctly, tested it visually, too. I am at the point of being convinced that the temp control switch has gone out, but I don't have a multimeter to check the resistance to make sure. Has anyone else run across this situation? I have had zero luck finding anything online other than the blend door is broken or the blend door actuator is broken. Any input would be much appreciated.

 

Welcome to the forum

The Blend door is run by the temp control switch
Simple test after engine is warmed up and idling
Set air direction to Panel
Turn fan on high
Turn Temp to HOT and should get nice warm air out
Turn Temp to COLD air should cool down to outside air temp, i.e. no air thru heater core, that's what the Blend door is for it blocks air going thru the heater core

If air stays warm then blend door is not working, period, there is no other option

The reason MAX AC cools down the air is because hot coolant flow thru the heater core is cut off by the by-pass in engine bay when MAX AC is selected, so core cools down

Google: Ford Ranger blend door actuator repair

Loads of videos
And the Blend door itself can break, well the square hole at the top that the actuator turns to move the door open and closed, rare but can happen, need to pull the whole dash to repair that
Picture here of that problem: https://www.therangerstation.com/Mag..._Axle_View.JPG


In the engine bay is the Blower box, it has the fan/blower and the AC Evaporator(the Cooling core) and then a rectangle hole thru the firewall by the evaporator and into the cab
In the cab on the other side of that hole is the Blend Door, it routes the air that comes from the fan and thru the evaporator and into the cab, either thru the heater core(HOT) or around the heater core(COLD) or anywhere in between
AC evaporator can only cool air down to 36-40deg, which is cold, but heater core can heat air to 180-190degF, so heater WINS, lol, always
AC just can't compete with a heater....................without the Blend Door