Heater Blend Door
 

I had done a search last week however can't seem to find it today. I have a '97 E150 with no heat. Since the temperature gauge reads normal and the hoses to the heater are warm, it would appear to be the blend door. I was trying to access the area however I was having some difficulty. Does anyone have experience or know where to look for photos? Winter is coming and I am going to need the heat.

The door is vacuum activated if I'm not mistaken. Ford used some pretty weird hard plastic vac lines that crack in areas exposed to heat as they age, by now your lines are likely bad. Also the vac reservior (coffee can behind the battery) is steel and prone to rusting.

Not enough vac and the door may not work, the engine may not run too great either.

The blend door breaking is a common problem on 1997s. Same problem happened to my 1997 E-350. Here is from alldata.com....

<<<1997-98 ECONOLINE

This TSB article is being republished in its entirety to include 1998 model year vehicles and correct the build date of the affected vehicles.

ISSUE:
Absence of temperature control on some vehicles may be due to the blend door actuator shaft having an interference tit with the blend door, thus causing the blend door to break.

ACTION:
Replace the heater case assembly with a revised heater case assembly. Refer to the following Service Procedure for details.

PART NUMBER PART NAME

F7UZ-18478-CA Heater case Assembly>>

There are a few posts and pictures in the heating and cooling section. (too bad search isn't working)

What I did to fix mine was: 1) drill a small hole through the top of the dash to where the blend door is 2)drill a small hole in the blend door 3)attach a piece of antenna wire so you have manual control of the blend door. Works fine, only drawback is you can not reach it from the drivers seat.

I have a '99 E350 and the blend door it is driven by an electrical motor with a feedback position sensor. When ever we don't have heat, I have the passenger reach under the dash board, there is the motor control in a white box on the right side. I tell them to rap on the white box. They look at me funny, tap the box, and then seconds later we have heat. Dealer wants $700 to replace the blend door. I'll use the passenger model as long as I can. Oh, and if it works, just don't set the heat to full. I find that it only sticks when set to full heat.

I have a 97 e-250 with the same problem. I diagnosed the problem down to the "white box. If you take it off. hook the wire connector back on and with the key on, rotate your heater knob from cold to hot. The shaft will rotate. my problem is: once its installed on the heater, it will allow the flap to drop but hangs up when it trys to raise it. It opens up and contains a circuit board and a small motor.The part number on the side of the box is: F68H-19E616-AA. In the Motors crash repair manual its :XC2Z18478BA. Cost $128.00 Book shows it fits 97-2003 models.
To get the heater passenger side cover off to view the flap. remove the dash lower, unbolt the tube under the dash and the very stubborn screws. Nothing on the engine side of the firewall needs to come off. Hope this helps.

I removed the motor on my van and tried the "blend door fix" with the nail in the motor shaft. The door is now open allowing the heat into the van. It will close if I move the control knob to cool. I was able to completely remove the blend door structure. While I had it out I attached a wire to the door. This aids in bringing the door to the open position since it seems the motor shaft still slips. The wire was an alternative to a complete blend door replacement. Since I completed the repair it is winter and I haven't had to worry about going to the cool setting.

Blend Door
 

Hi everyone, had problems with my blend door on my 98 e350 van. However I removed the white motor screwed to the right side of the heater box and checked it's movement with the heat adjust/ temperature control pot on the dash. My motor worked fine...they seem to be geared really low and move slow. However I noticed (with a mirror) the hole on the blend door that the motor output shaft slides into, was cracked open in 3 spots. This allowed the plastic to open up and the motor shaft would turn inside the blend door hole instead of driving it. I removed the heater core cover, heater core, and blend door assy. Removed the blend door from it's frame. Since all the plastic pieces were still there I melted a small slot under the broken drive tube on the blend door. Then epoxied the cracked areas of the tube back together with some quick set epoxy. Then I tightly wrapped some thin copper wire around the tube through the slot I had melted under the tube. Once wrapped I slathered the area with more epoxy. Wrapping the tube will prevent it from expanding or cracking again.
Reinstalled the blend door, and reassembled. The worst part of the whole job was removing the heater core to get to the blend door. The plastic cover over the heater core comes off with about 8 hex head screws but Ford thought they had to put a phillips head screw at the top which is hard to reach. Thanks guys.
As mentioned before the blend door control motor operates really slow so I know it's geared low and if your blend door gets stuck for any reason I believe the motor will overpower the plastic drive tube on the door and crack it open. Hope this helps

I have a similar problem in my '97 e150 conversion van. I can feel heat at the vents, but it doesn't blow out. I was told the actuator needs replacing, which is located on top of the dashboard, under a small access panel. Got the part, but can't figure out how to actually change it, w/o removing the entire dash! Any easier solutions? The metal arm should connect to this really fragile plastic piece, but my mechanic is worried about breaking it and screwing me up even more. At this point, I figure I sgould just buy one of those $20 dc defroster units...