Hi Everyone,

1998 2.5L manual ... recently purchased - very well cared for vehicle, except this issue.

Full A/C operation fine, but no temperature control.

When in any position other than A/C get ONLY full heat ... not mixing via the temperature rheostat.

Took dash apart and found everything wired, connected, etc ... main air door and other vacuum operated valve look like they are working OK.

Is the non-A/C temp controlled via the rheostat to a control of some sort that then changes to vacuum signal? It's been cold here and have not spent time, yet, tracing ...

One plastic housing next to thermostat there are two wired sensors ... or, is one of these a valve controlled by the rheostat?

Is non-A/C temperature mixing done by water restriction or by air mixing?

Best bet on what has failed or next steps?

Thanks to everyone!

George Stephenson

 

Welcome to FTE!

THis sounds like a blend door problem; it's fairly common. If you do a search in here you should find others that have delt with it as well as instructions on how to fix it yourself.

 

Thanks ... I, too, figured must be a blend door issue (inside the plenum box somewhere?), but the stat temp control hooked me into thinking something might simply be stuck in the hot water supply side ...

Is the control mechanism electric or vacuum for the water supply?

Thanks, again.

 

The blend door is electic, the hot water valve is vacuum.

If you get hot air in all positions except MAX AC I would suspect the BD too.

 

Thanks, much, to everyone ... will be doing the fix by the weekend ... looking for some warmer weather first.

Enjoy your holidays!

George

 

I think the fix worked ....!

Had to play a bit with the length of the nail-pin as I think it was jamming against the side of the tube causing there to be less than full deflection. Then, every time I would hold the actuator (by the way on my 1998 Ranger it was held in place by 3-8mm bolts, 2 facing rear and 1 facing front) in place the system worked fine, but when I bolted it in the full range of temp was no longer available ... I shimmed the actuator with a few thicknesses of tabe and back OK, now, I think. Perhaps the modified actuator was pushing down on the door causing it to jam somewhat?

Anyway - muchas thankos for a great fix!!!!!

George

 

Glad to hear you got it done!!!

 

As I reread the thread, it became apparent, well, at least to me, the broken pieces may be jamming the movement of the door. The great photos in the gallery on rebuilding the entire door with JB Weld are very helpful ... if I have continuing issues like lack of full movement in the blend door, I think I will do some surgery to get at the root cause ...

Does anyone know if the door itself is available as a new partf from Ford? Has anyone tracked down the OEM second or third tier supplier to Ford that made the assembly? (assuming it was not Ford, Inc.)

Thanks.