AC vs Max AC

[ctmpwrdcamry]

Whats the difference? My fiance has a 98 X with the SOHC. Her AC will work for a short while, maybe 30 seconds, then blow nothing but hot air. The air will only continue to blow cold if you switch it to and leave it on Max AC, why is this? And how do i fix it? Next month we are driving it from Ohio to Washington. Could be a long trip without AC.

 

[Willard]

I believe the only difference is with regular A/C, it pulls in outside air and cools it. With Max A/C, it closes off the outside air and recirculates it. That way it cools the already cool air. I know this is true for first gen's, and I don't think it's any different for you. Sounds like you have some problems with the rest of the system.

I would check the refrigerant level first, get one of those recharge bottles at the auto parts store.

 

[CDW6212R]

I have a similar problem, and mine isn't the freon or vacuum lines. I'm thinking likely it's the actuator or blend door which the actuator controls.

FYI, the MAX setting does simply divert the input air from outside to under the dash. It recirculates the air, that's the only difference. With the electronic AC(EATC), the MAX button also sets the temperature to 60. I wish that there was a recirculate button, I am going to integrate one someday. Regards,

 

[budwich]

you need to provide more info... on AC only, is your compressor cycling? short, long? IF short, then you likely have a "freon" issue, IF long, then its likely a door problem.

 

[96eb96]

Whats the difference? My fiance has a 98 X with the SOHC. Her AC will work for a short while, maybe 30 seconds, then blow nothing but hot air. The air will only continue to blow cold if you switch it to and leave it on Max AC, why is this? And how do i fix it? Next month we are driving it from Ohio to Washington. Could be a long trip without AC.

If max A/C is cold it is likely a blend door issue. There are many ways to go about fixing it.

The blend door and plenum mixes warm heater core air with cold evaporator air. Air blows thru the evaporator, and the blend door forces a certain percentage of the air thru the hot heater core or straight to the vents. This regulates air temp. If it is broken, it will sit in a random position or even change as you steer the vehicle!

Do you know why Max A/C allows cold air with a broken blend door? Because it closes the Heater control valve and stops flow to the heater core. This allows air to pass over the evaporator thru a cold heater core or straight thru into the vents depending where the door is broken.

I bet even with a broken blend door you can get A/C in the automatic A/C mode...just apply a constant vacuum to the heater control valve. Then you will be cooling the outside air, so while not a perfect solution the air won't be that cold.

 

[CDW6212R]

Not always, I have had my heater control valve disabled for two years. I get heat in the automatic position, and from warm to cool in MAX. I haven't looked hard for the problem, but I shall soon when I do the engine.

 

[TheJackal]

You can leave the A/C in Max A/C mode until you have time to fix it. You won't damage anything this way.

I actually run Max A/C all the time and believe it may be the reason why my Explorer has never had the blend door issue. With the heater core bypassed, there's no heat in the plenum, drying out the plastic door. That's only my 2¢ tho, don't know if there's any truth to it.

 

[CDW6212R]

Water in the heater core or not will not affect the plastic blend door. The blend door issue is supposed to be just the 95-97 models, the parts were changed for 1998.

 

[Mrrobalo]

I have the same problem with my 99 Eddy. I hit max and once cool I'll turn down the fan and can move the temp to 68 and thats as low as it will go before blowing hot.
I took off the actuator (inside the glove box) and re hooked it back up outside and changed the controls and nothing moved. I then took the part in half and touched the motor leads and the motor spins but not with it hooked up to the harness.
I left it out and went to work. On the way I turned and I heard the door shut and it started blowing hot.,hit max and back to cold till i turned it down and turned again same thing happened.?????
Between this and the drivers elect locks(no power at all to new actuator.) it is driving me nuts not being able to figure it out.

 

[ctmpwrdcamry]

This is all the infromation I have. The truck will not be in my possition until June, when it will just be the drive cross country. I will have no time to work on it. However, if the Max A/C works, then I will just leave it there.

 

[96eb96]

I have the same problem with my 99 Eddy. I hit max and once cool I'll turn down the fan and can move the temp to 68 and thats as low as it will go before blowing hot.
I took off the actuator (inside the glove box) and re hooked it back up outside and changed the controls and nothing moved. I then took the part in half and touched the motor leads and the motor spins but not with it hooked up to the harness.
I left it out and went to work. On the way I turned and I heard the door shut and it started blowing hot.,hit max and back to cold till i turned it down and turned again same thing happened.?????
Between this and the drivers elect locks(no power at all to new actuator.) it is driving me nuts not being able to figure it out.

Could this be a fuse or relay issue?

 

[Mrrobalo]

Is there a link someone could post as to where the
"Could this be a fuse or relay issue?" would be ?
Any help is appreacheated:exporange

 

[budwich]

Mrrobalo... IF you aren't getting power to your blender motor, then you need to check the fuse (with a meter) and then check follow the GY/ Y ? (at least in 96,... ? is that the diagram is hard to read). I doubt its the fuse as other things might not work.... does your cruise control work?

similarly, you need to track the wires for the actuator thru the door post in the driver's door where most people have problems.