EATC won't respond to temp adjustment

[tbone]

I did the O-ring repair a while back, and the air comes out where I want it, but the unit will not change the air temp. I assume that the signal is sent electronically rather than with a vacuum? Also when I try to do a self test, nothing happens.

Sounds like the unit is shot. Any advice is appreciated.

[Quasar3210]

So it sounds like it is stuck either full hot or full cold. Im thinking it will be blend door actuator motor. Its fairly common failure point.


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[tbone]

I can hear the blend door moving. But the return side of the heater hose is cold. How do I get to the heater control valve? Is it under the cowling? I looked in the firewall behind the glove compartment and could see nothing but tubing and wiring. My Haynes manual is worthless!


Rock Auto heater control valve pic
http://www.rockauto.com/getimage/getimage.php?imageurl=http%3A% 2F%2Fwww.rockauto.com%2Finfo%2 FMotorcraft%2FYG238-FRO.jpg&imagekey=380370-0&width=450

[tbone]

I disassembled my EATC to check everything and now the vent button doesn't work.

Ratfarts!

[fastblackmerc]

I've not seen a heater control valve. Will check the Ford Shop Manual to see if there is one... I think not.

The blend door controls the temperature.

Haynes manuals do suck.

Make sure the red electrical connector inside the EATC is on correctly.

[SC Cheesehead]

I've not seen a heater control valve. Will check the Ford Shop Manual to see if there is one... I think not.

The blend door controls the temperature.

Haynes manuals do suck.

Make sure the red electrical connector inside the EATC is on correctly.

^^^^^ That would be the first thing to check, if it continues, may be the circuit board; I had similar issues with mine and ended up replacing the EATC head.

[rayjay]

Everything is working on mine but the blower fan. :( I have not had time to even check the fuse. Hoping I can make it to SC this weekend. I can even hear the electronics telling the fan to move, but nada.

[tbone]

I've not seen a heater control valve. Will check the Ford Shop Manual to see if there is one... I think not.

The blend door controls the temperature.

Haynes manuals do suck.

Make sure the red electrical connector inside the EATC is on correctly.

Why would the return side of the heater core hose be cold when the hot side is toasty?

[tbone]

^^^^^ That would be the first thing to check, if it continues, may be the circuit board; I had similar issues with mine and ended up replacing the EATC head.


That's what I'm betting on. Ordered one from ebay. $189 with a $75 core. Oh well. Could be worse. :o

[tbone]

I just ran water through the heater to core to eliminate it as a possibility. Flows great. So it must eaither be the EATC or the blend mechanism.

[fastblackmerc]

Everything is working on mine but the blower fan. :( I have not had time to even check the fuse. Hoping I can make it to SC this weekend. I can even hear the electronics telling the fan to move, but nada.

Tap on the BCM. It will probably start working.

[rayjay]

Tap on the BCM. It will probably start working.

Gonna try it once I get my doctor appts out of the way today. :(

[CBT]

Gonna try it once I get my doctor appts out of the way today. :(
Think of a happy place while you are leant over....

[fastblackmerc]

Gonna try it once I get my doctor appts out of the way today. :(

I'll be in Wilmington, N.C. next Thursday, Friday, Saturday & Sunday. I can take a look at it on Friday or Saturday.

[tbone]

Thankfully it was the EATC and not the blend motor. The guy that sold me the new EATC said they currently have around 50 units with bad boards where they won't respond to heat adjustments. I did NOT want to pull the dash back.

[rayjay]

I took it apart per directions from a Member last night. A hot 26*F out. I don't know if just undoing the connector did it or the quick whack with a screw driver, but she's up and running again. If it goes above 32* here today i will take the connection apart and spray it with contact cleaner. Come on Sunday! Get me the heck outta this frigging ice box.....

Jim, I probably won't have time to take you up on your offer, but will in the future. Thanks!