The two switches that control the driver/passenger side heat or cold air do not seem to work anymore, I am not sure if something behind the dash came loose, but now all I get is heat with my A/C on the drivers side, and super cold air on the passenger side.

I have a feeling it has something to do with these switches, but where do I even begin trying to fix this before summer rolls around and I have no cold air?

1998 Dodge Grand Caravan 3.0L V6

 

Try this calibration procedure: (A/C must be working to perform this test otherwise you'll have flashing HVAC panel lights till you have the A/C fixed)

ACTUATOR CALIBRATION/DIAGNOSTICS AND COOLDOWN TEST
GENERAL INFORMATION
If the HVAC control module is replaced, the Calibration Diagnostic and Cooldown tests will need to be performed. Once this group of tests have successfully passed, they can be performed individually. The engine must be running during the test to provide hot coolant for the heater, A/C compressor operation and to assure that the actuators are calibrated correctly. The HVAC control module is capable of troubleshooting the system in approximately 120 seconds. If a condition is detected, an error code is displayed. The error code cannot be erased until the condition is repaired and the diagnostic test is performed. Check wire before replacing components, Refer to Wiring Diagrams.

CAUTION: Do not remove the actuators from the Heater-A/C unit assembly with power applied. Removal should only be done with the Ignition OFF. The actuators have no mechanical stops to limit the travel. If the actuator rotates and is not connected to the unit assembly, it will become out of calibration.

ACTUATOR CALIBRATION
Mode, Blend and Zone (if equipped) door calibration compensates for mechanical variations in the actuators, HVAC control module and its linkages. In-vehicle calibration can be entered from the control's front panel. If the REAR WIPE and INTERMITTENT LED's flash simultaneously when Ignition is cycled ON, the actuators have not been calibrated or during the previous calibration a failure occurred Radio Bezel and HVAC Control and Radio Bezel and HVAC Control, Rear Blower Motor Switch and Zone Control Diagnostics will always occur during Calibration Diagnostic and Cooldown test.

DIAGNOSTICS
During the Actuator calibration, diagnostics are performed on the actuators and evaporator temperature Fin Sensor. Once diagnostics are completed the REAR WIPER and INTERMITTENT LED's will flash to indicate either a successful calibration or the appropriate fail code(s) At this time manual testing of the Blend, Mode and Driver (if equipped) potentiometers can be performed. If a failure is detected during Diagnostics a fault will be set in the control. When Ignition is cycled OFF and then ON or Diagnostics is aborted, the REAR WIPER and INTERMITTENT LED's will flash simultaneously showing that a failure has occurred. The control will not indicate the fail code, but only that a failure had occurred during the last diagnostics test. The only way to clear the failure codes is repeat the Calibration Diagnostic and Cooldown test, after all repairs are completed.

COOLDOWN TEST
This test has been designed for performance testing of the A/C system at the manufacturing facility. If the HVAC control module is replaced, the Cooldown test will occur during Calibration test. Cooldown will not occur on Heater Only units. During the Cooldown test the control will monitor the temperature of the Fin Sensor. The A/C system must be able to bring the evaporator temperature down a predetermined minimum amount in less than 2 minutes.

CALIBRATION/COOLDOWN LED DISPLAY CODES
See chart for definition of flashing LED's. If no problems are found, the control functions normally.

LED'S PASS/FAIL CORRECTIVE ACTION
NO LED'S FLASHING-NORMAL OPERATION PASSED CALIBRATION, DIAGNOSTICS AND COOLDOWN NONE
REAR WIPER AND INTERMITTENT LED'S FLASH SIMULTANEOUSLY FAILED CALIBRATION DIAGNOSTICS RUN CALIBRATION TEST
A/C AND RECIRC LED'S FLASH SIMULTANEOUSLY FAILED COOLDOWN RUN COOLDOWN TEST
REAR WIPER AND INTERMITTENT LED'S ARE FLASHING SIMULTANEOUSLY A/C AND RECIRC LED'S ARE FLASHING SIMULTANEOUSLY FAILED CALIBRATION, DIAGNOSTICS AND FAILED COOLDOWN TEST RUN CALIBRATION TEST

CALIBRATION/DIAGNOSTICS TEST ENTRY
TO INITIATE TESTS:
Set Blower motor ON HIGH
Set Mode position to Panel
Open all A/C outlets
Set Temperature to Cold (Both slide pots if equipped)
Depress WASH and REAR WIPER button simultaneously for 5 Seconds (Until all LED's light)
RESULTS:
All LED's will turn on for 5 Seconds
Calibration Test is running when REAR WIPER and INTERMITTENT are alternately flashing. Cooldown test is running if A/C and RECIRC are alternately flashing.
Acceptable results is REAR WIPER LED is the only LED flashing. Push Rear Wiper to exit.
After all tests have passed, Calibration Diagnostics and Cooldown can be run separately.
COOLDOWN TEST ENTRY
TO INITIATE TESTS:
Set Blower motor ON HIGH
Set Mode position to Panel
Open all A/C outlets
Set Temperature to Cold (Both slide pots if equipped)
Depress WASH and A/C simultaneously for 5 Seconds
NOTE: Prior to start of test, If the evaporator is already cold, the system will fail test. To correct, operate system with A/C OFF and the blower motor ON high for three minutes prior to starting test.

RESULTS:
All LED's will turn on for 5 Seconds
Cooldown Test is running when A/C and RECIRC. are alternately flashing. If A/C and RECIRC. are flashing simultaneously, Cooldown has failed.
CALIBRATION DIAGNOSTICS AND COOLDOWN ABORT
Test can be aborted by doing one of the following:

Depressing Rear Window Defogger, RECIRC and Rear Wiper buttons.
Cycling Ignition OFF and then ON.
Control will automatically abort after 15 minutes from the time Calibration Diagnostics and Cooldown was entered.
The HVAC control module will return to normal operation or may indicate unsuccessful Calibration Diagnostics or Cooldown test by LED's flashing simultaneously.

EEPROM DATA
Calibration Diagnostics, Cooldown Status and evaporator temperature Fin Sensor values are stored in an EEPROM memory internal to the control. The microcomputer within the HVAC control module uses this information:

To determine if Cooldown needs to run
For proper position of the Heater-A/C unit assembly doors
ACTUATOR CALIBRATION AND DIAGNOSTICS
NOTE: Do not run actuators unless they are properly mounted on the HVAC control module.

Actuator end point calibration takes approximately 60 seconds. The REAR WIPER and INTERMITTENT LED's will flash alternately during the test. The control will cycle the Blend actuator(s) to the Heat stop first then back to Cold. After the Blend actuator(s) have been calibrated the Mode actuator will be cycled to Defrost and then to Panel. Successful calibration is defined as actuator travel falling within their minimum and maximum limits.

BLEND/PASSENGER ACTUATOR BACKGROUND
The Blend/Passenger Actuator can move the temperature door in two directions. When the voltage at Pin 12 of the control module is high, about 11.5 volts, and the voltage at Pin 17 is low, about 1.5 volts, the door will move towards the Heat position. When Pin 17 is High and Pin 12 is Low the door will move towards the Cold position. When both Pins are high or both Pins are low, the actuator will not move. The Blend/Passenger feedback signal is a voltage signal that is supplied by the actuator to the control. The signal will be about 4.0 volts in the Heat position and 1.0 volt in the Cold position. As the position of the Blend/Passenger actuator changes, so will the feedback signal. The feedback signal is necessary for the correct positioning of the temperature door.

DRIVER ACTUATOR BACKGROUND
The Driver Actuator can move the temperature door in two directions. When the voltage at Pin 15 of the control module is high, about 11.5 volts, and the voltage at Pin 13 is low, about 1.5 volts the door will move towards the Cold position. When Pin 13 is High and Pin 15 is Low the door will move towards the Heat position. When both Pins are high or when both Pins are low, the actuator will not move. The Driver feedback signal is a voltage signal that is supplied by the actuator to the control. The signal will be about 4.0 volts in the Heat position and 1.0 volt in the Cold position. As the position of the Driver Actuator changes, so will the feedback signal. The feedback signal is necessary for the correct positioning of the temperature door.

MODE ACTUATOR BACKGROUND
The Mode actuator can move the mode door in two directions. When the voltage at Pin 18 of the control module is high, about 11.5 volts, and the voltage at Pin 12 is low, about 1.5 volts the door will move towards the Panel position. When Pin 12 is High and Pin 18 is Low the door will move towards the Defrost position. When both Pin are high or when both Pins are low, the actuator will not move. The Mode door feedback signal is a voltage signal that is supplied by the actuator to the control. The signal will be about 4.5 volts in the Panel position and 0.5 volts in the Defrost position. As the position of the Mode actuator changes, so will the feedback signal. The feedback signal is necessary for the correct positioning of the mode door.

FAIL CODES/LEVEL DISPLAY
Fail Codes/Level are displayed using the REAR WIPER and INTERMITTENT LED's flashing in the sequence indicated below. The REAR WIPER LED represents the Level and the INTERMITTENT LED represents the Value. After Calibration/Diagnostics is completed, the control will begin flashing Level 1 codes. Depressing the WASH button will cycle to Level 2, depressing WASH again will cycle to Level 3. Each time the WASH button is depressed will cycle to the next level. After Level 5 is reached, you will cycle back to Level 1. If the Control is a Heater Only you will only cycle from Levels 1 to 3.

WIPE BUTTON LED
LEVEL DISPLAY
1 FAIL CODES
2 MODE POTENTIOMETER TEST
3 BLEND/PASS. POTENTIOMETER TEST
4 EVAPORATOR PROBE (A/C AND ZONE UNITS ONLY)
5 DRIVER POTENTIOMETER (ZONE UNITS ONLY)

LEVEL 1 - FAILURE CODE VALUES (INTERMITTENT WIPE BUTTON LED)
CODE DEFINITION
0 PASSED ALL TESTS
1 MODE ACTUATOR DID NOT REACH DEFROST POSITION
2 MODE ACTUATOR DID NOT REACH PANEL POSITION
3 BLEND/PASS. ACTUATOR DID NOT REACH COLD STOP
4 BLEND PASS. ACTUATOR DID NOT REACH HEAT STOP
5 EVAPORATOR PROBE OPEN
6 EVAPORATOR PROBE SHORTED
7 DRIVER ACTUATOR DID NOT REACH COLD STOP
8 ZONE/DRIVER ACTUATOR DID NOT REACH HEAT STOP
9 CONTROL HEAD INTERNAL FAILURE

TEMPERATURE AND MODE POTENTIOMETER DIAGNOSTICS
The Temperature and Mode Potentiometer can be tested after calibration is complete by pressing the WASH button and cycling to Levels 2, 3 or 5 as displayed by the REAR WIPER LED. On Heater Only units you can only cycle to Levels 2 and 3. In each individual test the INTERMITTENT LED flash rate will change as the Temperature or Mode potentiometer is moved from one end to the other, see Potentiometer vs. Position and Flash Rate table.

POTENTIOMETER vs. POSITION AND FLASH RATE
POTENTIOMETER INTERMITTENT LED FASTER FLASH RATE INTERMITTENT LED SLOWER FLASH RATE
MODE PANEL DEFROST
BLEND/PASS. HOT COLD
DRIVER HOT COLD

EVAPORATOR PROBE TEMPERATURE DIAGNOSTICS
The evaporator probe can be tested by using the INTERMITTENT LED to display the actual temperature the sensor is reading. The HVAC control module can only display temperatures from 1 to 99 degrees. To read the temperature, perform the following:

Set Blower motor to any speed other than OFF
Set A/C to ON, if A/C Clutch does not engage make sure Fail Codes 5 and 6 are cleared.To clear the error code 5 and 6 the evaporator probe and/or the wiring repair needs to be completed. Then, press and hold the intermittent wipe button for 5 seconds.
Run Diagnostics (Depress REAR WIPER and REAR WASH)
When Diagnostics is complete, Cycle to Level 4.
Display Sequence is as follows:

REAR WIPER LED will display the Level
INTERMITTENT LED will display ten's digit
Short Pause
INTERMITTENT LED will display the one's digit.
The HVAC control module will continue to cycle the Level and then Temperature until the level is changed or Calibration Diagnostics and Cooldown test is exited.
__________________
Dodge Master Tech.

 

Thanks for the reply, when I bought the van about a year ago I had no rear A/C, I couldn't figure out if it wasn't included in my model, or of it was a bend/acuator issue in the back. I tried the calibration, but it never got the rear A/C to work, and I could never get rid of the blinking lights on the two buttons on the dash.

I have a feeling this heat on the driver side has something to do with the passenger/driver hot/cold switches, since right after messing with them is when it got stuck on hot.

 

I tried the calibration again, but it didn't seem to change anything, I still have the blinking lights on the 2 wiper buttons, and no luck getting cold air on the driver side. Do I need to pull the dash apart or is there an easier way to get behind that switch?

 

I am still have no luck getting it to blow cold on the drivers side. Occasionaly when I move the switch from cold to hot I hear an actuator or motor sound coming from under the steering wheel, any idea if that's related to my issue? I only got the noise a few times during the numerous times I have tinkered with the buttons/config/calibration routine.

I still get nothing but two blinking lights on the windshield wiper buttons on the dash but I always had those even when the A/C worked. I live in Arizona so it will be warm by April.

 

Radiator coolant is always flowing into the HVAC unit under the dash. Whether you get heated or cooled air is solely dependent on the position of the blend/mode doors. Your problem is almost always caused by a bad driver's side blend door actuator. That's not to say everything else is eliminated ie wiring or control panel. These actuators are mounted on the driver's side of the HVAC unit. The noise you're hearing is one of three actuators trying to move. You'll have to get under the dash and investigate. You didn't state your model year so I took a stab and found this diagram for a 2001. It shows the location and explains how to gain access:http://www.justanswer.com/dodge/3sj8...ngine-van.html

 

Thanks for the info, so is this something someone who is somewhat handy with cars can try out, or do I need to take this to a professional? My van is only worth $1k, so putting anything over $100 into it might be pointless.

I see the diagrams on that link, but I don't exactly understand what part of the car they are in, is this under the dask, or near the compressor under the hood?

Sorry I forgot to mention it's a 1998 with the 3.0L motor.

I will search around on here and other sites some more or even YouTube to see if I can find any videos on this in the meantime.

 

I replaced one actuator years ago. I don't remember it being a major deal except it was awkward to get to. I want to say removing the climate control panel and/or radio helped but not sure.

Picture the driver's side dash and steering column removed and you sitting where they were, looking towards the passenger side. That's what the diagram depicts. The actuators are behind the dash roughly in line with the left side of the climate control panel. A smart precaution: disconnect the negative battery cable anytime you're working under the dash. Nobody needs an unexpected airbag deployment.

This is a diagram for a 1998 according to the source: http://ww2.justanswer.com/uploads/do...blend_door.gif

 

That doesn't sound too bad, I haven't had any issues with the repairs I have done so far myself so I might give it a shot. I will make sure to disconnect the battery, thanks for the heads up.

 

Sounds good. Keep us updated.