tarafied1
Active Member
AC only blows thru defrost! I had the same issue that many have stated in the treads and often they ended with, "you must have a vacuum leak" but no real solution posted.
Some have found the check valve is a problem or one of the lines going to it or from were cracked. Mine was okay.
I checked the vacuum going into the EATC by discontecting it from the EATC and checking vacuum on the black 1/8" hose. It was 20inHG, same as engine vacuum. That confirmed that I didn't have any vacuum leaks under the hood. I found the actuator for the vents (near the steering column) and checked the vacuum at the line going into the actuator. It was the red 1/8" tube. It was only about 4inHG. I used my vacuum pump and it took at least 10inHG to open the actuator all the way.
SO I figure the EATC was bad. I found a link on a Mercury Marauder forum talking about how to replace the O-rings in the EATC. I replaced the O-rings and my AC now works like it is supposed to.
http://www.mercurymarauder.net/forums/showthread.php?t=36922&highlight=EATC&page=12
The T20 Torx Screws on the back of the EATC unit (mine was 5.5mm (1/4"-ish) capscrews).
The solenoid connector (red connector in pic, mine was white)
The 1st pic shows screws that have to be removed to access the solenoids, my solenoids were in a metal frame, spot-welded at the outside ends, and plugged into a black-plastic manifold that has similar appearance to the pictures (see 2nd picture). To remove the solenoids, I drilled through the spotwelds - the frame had locating dimples on the bottom side (the side without the solenoid 'ears'), and I used a 1/16" bit. Then I flipped the frame, and with a 1/8" bit, broke the ears free of the weld. To reinstall, just solder them back together. (sorry I didn't stop to take pics).
Tabs that have to be straightened to remove the plunger
The plunger with original O ring
Plunger with new O ring
Some have found the check valve is a problem or one of the lines going to it or from were cracked. Mine was okay.
I checked the vacuum going into the EATC by discontecting it from the EATC and checking vacuum on the black 1/8" hose. It was 20inHG, same as engine vacuum. That confirmed that I didn't have any vacuum leaks under the hood. I found the actuator for the vents (near the steering column) and checked the vacuum at the line going into the actuator. It was the red 1/8" tube. It was only about 4inHG. I used my vacuum pump and it took at least 10inHG to open the actuator all the way.
SO I figure the EATC was bad. I found a link on a Mercury Marauder forum talking about how to replace the O-rings in the EATC. I replaced the O-rings and my AC now works like it is supposed to.
http://www.mercurymarauder.net/forums/showthread.php?t=36922&highlight=EATC&page=12
The T20 Torx Screws on the back of the EATC unit (mine was 5.5mm (1/4"-ish) capscrews).
The solenoid connector (red connector in pic, mine was white)
The 1st pic shows screws that have to be removed to access the solenoids, my solenoids were in a metal frame, spot-welded at the outside ends, and plugged into a black-plastic manifold that has similar appearance to the pictures (see 2nd picture). To remove the solenoids, I drilled through the spotwelds - the frame had locating dimples on the bottom side (the side without the solenoid 'ears'), and I used a 1/16" bit. Then I flipped the frame, and with a 1/8" bit, broke the ears free of the weld. To reinstall, just solder them back together. (sorry I didn't stop to take pics).
Tabs that have to be straightened to remove the plunger
The plunger with original O ring
Plunger with new O ring
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