help-for a 86 cougar xr7- ac and vent settings blowing though defroster ,on top. change dash control,that is not the problem. can anybody help me out.info where to look,step by step instructions. me and some car people cant solve the problem.figure its some kind of relay or vacuum switching. is these parts in dash or under hood. can somebody coach me though this in simple laymen terms.next step is ford/mercury dealer for problem. dont want to do that,funds are limited.
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I'm having a very similar problem on my 87 LX with the electronic climate control system (both depend on vacuum). However my problem is intermittent with the doors sometimes working. But at times all I get is cold air blasting out the defrost. I'm suspecting there's a main source vacuum issue.
When I get home today the first thing I'm going to check are the hoses at the MVAC vacuum reservoir.
I found this thread which at least tells me where it is. Thought it might help you too, maybe not.
http://www.foxtbirdcougarforums.com/showthread.php?6839-Where-is-the-MVAC-vacuum-reservoir-supposed-to-go
It's kinda hard to tell at first where it is from the photos. But it's located up under the driver's side fender. Looks like you'll need to remove the wheel to get a clear shot up there.
EATC does not use vacuum to control the doors. The doors are controlled by electric motors. The motors are controlled by the EATC Control Assembly's microprocessor.
You're right, my bad on that one. I thought there was some integration. Maybe softouch's diagram will help. I'm studying them for my issue. There's an electrical and non-electrical schematic at the thread below.
http://www.foxtbirdcougarforums.com/showthread.php?32328-85-88-non-auto-climate-control-ac-heater-control&highlight=blend+door
The 84 ATC does use vacuum. The 87 EATC does not.
Here is the 87 EVTM diagram for EATC.