QuestionQUESTION: I have a 1999 Town & Country. Granted it has had it's fair share of problems along the way, at 216,000 miles what do you expect ! :-) But we are trying to maintain as well as possible to extend its life. In the past month, the air stopped working in the rear of the van. It seemed that one day I started hearing a noise in the back hatch. I pulled over not knowing the cause and traced it to the slots on the right of the "trunk" compartment. Not sure what it is - a return for the A/C???? Now the heat has stopped working 97% of the time. If you turn it off and on, hot to cold, floor to dash, you can sometimes "trick" it to some on for a bit. (FYI: The passenger side has been blowing cold instead of heat since last year, but the middle, under radio controls, and driver has been fine til this episode) So now - don't even know where to begin to diagnose this problem, which isn't too fun - since it's COLD out!!!! Any help would be wonderful!
ANSWER: Hi Kristie,
The noise may have been the blower motor binding or fan attached thereto rubbing on the housing. The power for that blower comes from fuse 11 (20 amp) in the fuse box that is under the dash, so check that fuse to start. If it is OK then probably the motor for the blower is out, but try to see if the rear control switch will cause the blower to run. Let me know if the blower is out and you want to change it yourself and I can give you the procedure.
On the front air control problems, the unit has a procedure to calibrate the operation of the air doors and also to diagnose problems and tell you the cause by means of patterns of flashing lights on the control panel. The engine must be running. Set the blower on HIGH, set mode to the PANEL position, open all AC outlets, Set temperature slide pot(s) to COLD, Depress WASH and REAR WIPER simultaneously for 5 seconds (Until all LED's light). The LED's will stay on for 5 seconds. Calibration tests are running when the rear wiper and intermittent are alternatively flashing. Cooldown test is running when the A/C and recirc lights are flashing.
Acceptable result is when the rear wiper only LED is flashing.
Push rear wiper button to exit.
Interpretation of codes (presumably stored if you don't get the above result) is an involved process for which it would be better to xerox copy and postal mail you the pages.
So see whether your unit seems to behave according to what I have described, and please let me know.
Roland
---------- FOLLOW-UP ----------
QUESTION: Ok - here are my findings - I turn out the rear air along with front and it blows but not cold, but my husband checked the refrigerant and it will not take any more.
Ok - as for the diagnostic. The lights started flashing doing the calibration - they blinked for 50 sec then just stopped - it never illuminated the A/C, redirect for the cool down.
What do you think??
'
ANSWER: I am not certain what to make of what you told me other than that the blower in the rear is working. The question is why aren't you getting heat. The cooldown part of the test is relevant for the AC needed in warm weather so let us set that aside for now.
The lack of hear from the rear could be due to either a poor flow rate of heated water from the engine due to a partially clogged heater core in the back or due to a poorly operating air mixing door in the rear. I would start by checking the two heater flow lines that come from the engine and run along the right side of the van on the underside. See if the both of the lines are similarly warm (though one will be clearly warmer) or if one is warm and the other cold (which indicates restricted flow). If they are both warm and you don't get heat in the rear, then the door that should direct air flow across the heater core in the rear is not doing so.
The best solution, if you want to try to fix it yourselves, is for me to xerox copy and send you the pages from the shop manual I have for the '98 model . It costs me 10 cents a side to do the copying and there are about 49 pages. If you would would send $6 to cover copying and postage, I will send you the pages. I believe the problems are sufficient that you would be needing the manual to effective fix your problems. I'll await further results and to see whether having run the 'calibration' part of the diagnosis whether any improvements may have been effected already.
Roland
Here is a more complete protocol for the diagnosis/cooldown testing
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 table for definition of flashing LED's. If no problems are found, the control functions normally.
CALIBRATION/COOLDOWN LED DISPLAY CODES
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
---------- FOLLOW-UP ----------
QUESTION: I did the diagnostic for cool down and result were
A/C and RECIRC. are flashing simultaneously.
AnswerThis show there is an abnormality on the AC cooldown test result. But you have to press some more buttons and read some more charts to interpret. It really is necessary for you to have the pages. If you just want the pages about doing/interpreting the tests let me know a postal address and I will send you the pages. If you would be so kind as to send me back a couple of 42 cent stamps that would be appreciated.
Roland
