1999 Crown Vic AC

[keely111]

Suddenly my Crown Vic is pouring really hot air out the a/c vents when the controls are set to Air conditioning.

Any ideas?

[way2old]

Blown fuse, relay, refrigerant leaked out, low pressure cut out switch, clutch wiring bad, diode bad. Is the compressor running when you turn on the A/C? Start with that information and post back. Thanks.

[keely111]

Yes, the compressor is spinning. I checked the fuse with a voltohmeter and that looked okay.

When the A/c is on it feels like the outside air is being heated up then blowing out the vents. It is definitely hotter than just outside air.

Pardon my lack of using the proper term but, the tall black cylinder seems to feel cool when the a/c is engaged. After shutting it off I hear a gassy sound from that area.

I'd appreciate being as descriptive as you can as I've never worked on a car's a/c before. I'll leave any freon issues to someone who knows what they are doing and has the right tools but, I can check for loose hoses, bum connections etc.

I really appreciate your help.

John Keely

[way2old]

It sounds like the blend door motor is hung in the heat position. There is a small motor on top of the A/C housing behind the glove box. This controls the heat or cold air that is blown into the car. Since the compressor is working, I am going to assume the refrigerant charge is OK. It is possible the switch in the dash has gone south and not changing the blend door.

[keely111]

Is there a way for me to test this from under the hood or inside the car without taking the dash apart?

Is there a way for me to easily replace this switch myself?


Many thanks - your help is appreciated.

[keely111]

This car has the Automatic temp control system. Does this affect the diagnosis? DOes that who panel have to go if one switch is misbehaving?

Thanks

[way2old]

Start with this test. There is nothing to dis-assemble yet.


Electronic Automatic Temperature Control Module Self-Test

The EATC module self-test will not detect concerns associated with data link messages like engine coolant temperature or vehicle speed signals. A NGS tester must be used to retrieve these concerns.
The EATC module self-test will detect concerns in the system control functions and will display hard diagnostic trouble codes (DTCs) in addition to intermittent diagnostic trouble codes for concerns that occur during system operation. The vehicle interior temperature should be between 4°-32°C (40-90°F) when carrying out the self-test. If the temperatures are not within the specified ranges, false in-car temperature sensor DTCs will be displayed.
The self-test can be initiated at any time. Normal operation of the system stops when the self-test is activated.
To enter the self-test, press the OFF and FLOOR buttons simultaneously and then press the AUTOMATIC button within two seconds. The display will show a pulse tracer going around the center of the display window. The test may run as long as 30 seconds. Record all DTCs displayed.
If any DTCs appear during the self-test, follow the diagnostics procedure given under ACTION for each DTC given.
If a condition exists but no DTCs appear during the self-test, refer to the Symptom Chart Condition: The EATC System Is Inoperative, Intermittent or Improper Operation.
To exit self-test and retain all intermittent DTCs, push the blue (cooler) button. The control will exit self-test, retain all intermittent diagnostic trouble codes and then turn OFF (display blank).
To exit the self-test and clear all DTCs, press the DEFROST button. The vacuum fluorescent display window will show 888 and all function symbols for one second. Then, the EATC control assembly will turn OFF (display blank) and all DTCs will be cleared.
Always exit the self-test before powering the system down (system turned OFF).
Intermittent DTCs will be deleted after 80 ignition switch ON cycles after the intermittent condition occurs.

[keely111]

I ran the diagnostic and got a "24".

Thanks!

John Keely

[way2old]

The 024 hard fault is for a blend door problem. Now it is time to tear apart and check the operation of the blend door and wiring. Are you going to do it, or have it done?

[keely111]

Well, I guess it depends.

If I have to tear the entire dash out to do it - that may be getting in over my head. If it is a matter of undoing some screws and light disassembly / reassembly I'd go for it.

Like I said I've never done major work on a car but, I am pretty handy and mechanically inclined.

All I have are basic tools - nothing specific to automotive work.

What would you recommend?

[way2old]

As a start, you can pull the glove box out and look up in the top rear of the hole. There should be a little motor in there. Turn key on and see if you can feel, hear or see the motor moving. If the motor is moving, the blend door is probably broken and requires some work. If it is not moving, then it requires electrical diagnosis.

[keely111]

I think I can do that much. Any tips or tricks for getting the glove box out?

Many thanks for your ongoing help it is very much appreciated.

John K

[way2old]

Just look at how it is installed. There may be a few screws that hold the inside portion in. The door should drop down when the little straps are removed. Some of the inside portions just pull out. Just look at it before you grab a Sawzall.

[keely111]

I'm going to pull the glove box this weekend.

Once I'm in there what/how can I check the motor for the blender to see if that is the problem or if it is the blender door itself. Are there contacts I can clip 12 volts to to see if it works out of the car or ??

Is the blender motor replaceable by just going through the glove box opening or.....

Many thanks,

John Keely

[way2old]

Easiest way to check is to feel it while the temperature control is moved. If you can feel the motor working, try it again while looking at the little space under it to see if the door is moving. It is hard to see the door rod though, really close clearance. By any chance, has anyone dropped anything down the defroster vents? If so, it can drop all the way to the door and block it from moving. Good luck.