97 Heater Problem

[4x4black97]

My heater is either on full or off. The controlswitch does not adjust the valve. I've found the valve and used a wire to make adjust it. Is this valve vacuum controlled? How do I tell if it is the control switch inside on dash or this vlave?

 

[BrooklynBay]

Welcome to this forum! If you are referring to the heater control valve, then which part did you jump with a piece of wire?

 

[4x4black97]

I used a wire to pull the valve in the collant line partially closed manually, I did not jumper anything. THis has one large wire or tube goping to it so I thinmk it is controlled by vacuum, there is no ground wire.

 

[Turdle]

Try this thread-it shows the vaccum lines pretty well. I suspect the reservoir globe has become disconnected--
It's in there--

http://www.explorerforum.com/forums/showthread.php?t=192842&highlight=ac+defrost

 

[4x4black97]

97 Heater Problem - blend door actuator - temperature door

jtsmith - thanks for all the good information! The valve I used a wire to partially close is the coolant bypass valve. I thought this controlled the coolant flow to the heater's exchanger and I see now that is just shuts when the AC is on. So my problem must be in the center switch with the blue and red colors for cold and hot. And now I see it is the blend switch controlling a temeperature door, I assume also using a vacuum valve located somewhere or is it electronic?

I'll have some fun tracking this down this weekend.

Thanks again for your help!

 

[btexpress]

Temp control is electronic, the motor is behind the glovebox, and these are prone to failure, also the blend door ver commonly breaks, and usually sticks in the hot position

 

[4x4black97]

btexpress - thanks for the information!

 

[4x4black97]

Heater Problem

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It was the connection between the motor and the blend door. I took the whole dash out to see the problem. I bought a new motor and tried it and the old one by hooking the batery back up and using the switch to move the motors. There is a shaft in the door with a square hole that the motor sit in that was broken. So I tried epoxying it. You can get the motor out by removing the glove box. It is white and sits on top of the ducting. You can pry it up and out to test it. You can use a mirror to see if it is broken. I epoxied the old motor shaft to the blend door shaft and will try it after the cold weather is over to see if it holds.

If the epoxy doesn't hold I since found an easier way to repair it on this same forum. Here's the link http://www.chrisfransen.com/Ford_Blend_Door_Fix/. There was another one that just talked about moving it manually once or twice per year. If you want to move it so it is always hot another way would be to use the vacuum controlled vlave under the hood and install a chike calbe to adjust it manually or install a heater vlave and choke cable separately. I did this on a 78 Mercedes and it works very well.

It might help others to post this since it took me awhile to find the forum link, after I had taken the dash out. It ook awhile to get it out, but went back pretty easy, after I found out where all the screws and nuts were, and even better I did not break anything!

Good luck.

 

[btexpress]

I have heard of several supposedly quick fixes for this blend door problem, but not the one you linked. I don't know how long it took him to do that setup, but I am sure I could do the job right, replace the plenum, and do it in less time as he did that "repair". But I relaize some don't want to pay to have the job done correctly, so have at it.

I can see all kinds of problems with epoxy the way you are using it.