1995 Explorer Limited heat Problem

[ExplorerSHO]

I Loose my heat from time to time. I have an automatic temperature display.
What I mean is when set the thermostat to say 85 degrees it blows out cold air. I will flip it back and forth between AC 60 Degrees and auto 90 degrees over and over until I get the heat to kick in.
I can hear the Mixing door closing so I don’t think it’s the mixing door or the actuator.
I flushed the coolant, changed the thermostat and I can feel the inlet and out let hose of the heather core and there both hot and seems to have it flowing. I do not smell any antifreeze and I can’t find any leeks.
I have been without heat for 2 months now and out of the blue It started to work on its own last night for the first time in 2 months.
Please help I’m Stuck.

 

[koda2000]

there can be problems within the EATC module. there are 4 small solenoids inside this module that control various functions via vaccum. over time the small o-rings inside the solenoids wear out. this causes a small loss of vaccum which then causes a particular function not to kick in (eg: temp). there are also several diagnostics which you can perform on the EATC electronics (some combination of pressing several buttons at the same time). you can find replacement EATC modules on ebay for between $50-$100 (quality unkown) or you can get your's repaired (electronics and o-rings for $99)

 

[ExplorerSHO]

Really Where canI get it repaired for $99?

Do you know how to check it for codes and Where I can go to get it repaired?

 

[koda2000]

Do you know how to check it for codes and Where I can go to get it repaired?

i'll check to see if i kept any of the info i found on-line while researching. you can try searching my threads to see if i put any details in them.

here's one: further on-line research has possibly pointed me in the right direction (or at least a direction). from what i've read on the Mercury Marauder forum, and assuming the Mountaineer EATC is similar, the problem may be that the EATC module solenoid armature o-rings are worn and not holding vacuum. i have a vacuum test to perform tomorrow and, if it's not too hard to remove the module, i may swap it with the one out of my Explorer and see if that solves the mystery. if it does i can try replacing the o-rings or send the module out for repair.

BTW, it's easy to pull out the EATC module. radio bezel, a couple of screws, a wire plug and the vaccum lines.

here the link, it was in my recycle bin...

http://www.youtube.com/watch?v=hAqE-oYnvlQ

 

[Aluminum]

I Know That Most Explorers And Expeditions Have The Heater Core Go Out Sooner or Later I Know 3 People Whose Went Out.

 

[koda2000]

I Know That Most Explorers And Expeditions Have The Heater Core Go Out Sooner or Later I Know 3 People Whose Went Out.

well, you can always try back-flushing the core, but you originally stated you didn't have any leaks and that both the heater hoses were hot. clogged heater cores usually result from lack of maintainance of the cooling system.