98 Mercury Mountaineer Heater Valve Problems

[johnyakimo1855]

I have a 98 Mercury Mountaineer that has the EATC. My daughter brought it down with no hot air blowing out the vents. I fount the electric blend door not working. I replaced it and the fuse and got it working. Sent her home. She called and said she has A/C at idle but gets hot as soon as she gives it even a lil gas. I sent her to a local old school shop I know up where she lives and they said the heater valve was bad, so they replaced. They called to inform me that the valve would still open full as soon as a little gas is given so they and that it must be a vacuum leak somewhere in the system and they clamped it off. So now she has no heat. I checked the vacuum lines with a smoke machine and had nothing major of concern (had VERY little smoke coming from EATC) . I though about sending in the EATC and have rebuilt but when I called the place they said it would not fix the particular problem I'm having, that it would only fix the air diversion problem. The heater valve goes straight into the EATC so if the ORING is out or giving out wouldn't it allow this to happen. I do not know but need some help here, if I take it somewhere there gonna charge me $300-500 to not fix the problem. It has to be something simple I'm missing. I'm pretty well versed on working an anything mechanical but I'm needing some direction here. Thanks Guys!!!

 

[J_C]

If it's just a matter of worn out o-rings, have you considered rebuilding the EATC head unit yourself?

Ford EATC Repair & O-ring Replacement Tutorial

Step by step guide on how to replace the solenoid o-rings on Ford's EATC module. If your heater and air conditioning are only blowing through the defrost vent, it's likely that your EATC can be repaired by simply replacing the o-rings in the modules vacuum solenoids, avoiding a costly replacement.

www.f150hub.com

Apparently some are spot welded and harder to do than others.

 

[donalds]

Great info there ^^^^

 

[johnyakimo1855]

If it's just a matter of worn out o-rings, have you considered rebuilding the EATC head unit yourself?

Ford EATC Repair & O-ring Replacement Tutorial

Step by step guide on how to replace the solenoid o-rings on Ford's EATC module. If your heater and air conditioning are only blowing through the defrost vent, it's likely that your EATC can be repaired by simply replacing the o-rings in the modules vacuum solenoids, avoiding a costly replacement.

www.f150hub.com

Apparently some are spot welded and harder to do than others.

I will go ahead and rebuild. I will report back what i find. Thanks Gentlemen

 

[fast_dave]

Just sayin' along with J_C @ donalds, with EATC, 99.9% of the issues are almost always O-Ring related.

Your mileage may vary -