QuestionI've read what I could find that was similar to my issue, but am just not hitting
it on the head. Long story as short as I can make it:
My 350,000 miles `96 G.Voyager 3.3L A/C system has the Driver/Passenger
as well as Front/Rear blower & temp controls on it. A/C and heat both
working fine as near as I can tell, but recently, the Front/Left quadrant
(drivers area) appears to be stuck blowing heat, no matter what the controls
are set to, and even though all other vents in the other 3 quadrants are
blowing cold- or whatever you're calling for at the time. When I slide the
Driver's side temp control from hot to cold, I can hear a distinct change in the
pitch & sound of the air (or heat) as it changes temperature and passes thru
all the other vents (front passenger side, as well as rear vents). Yet nothing
changes about the (guessing) 200 degree air coming from the center console,
far left side dash and the left half ONLY of the defroster vent. The right side
of the defroster vent is blowing cold (while in A/C mode) while the left side is
blowing hot as all git-out. In Texas, in the summer, we have a tendency to
notice these things. ;)
I'm envisioning a stuck vent door, but don't know where I should begin
looking for it (aside from "under the dash somewhere"). So I suppose this is
two questions.
1) Where is the culprit likely to be located? and,
2) Is it something/somewhere I can get to without an excessive amount of
disassembly? (dashboard I don't mind too much, but if I've gotta pull the
steering column or something equally enthralling, I'll be off to the dealers for
the repair).
Thanks in advance.
AnswerHi DJ,
There are electro-mechanical actuators on the left end of the underdash air housing, one each for the passenger and the driver and one for the mode of distribution. Those are accessible from underneath but first I would suggest taking advantage of a calibration procedure and fault self-diagnostic capability that is built-in to the unit. Here is a copy of the description from the manual. Doing the calibration may straighten out the problem with no intervention, and if not, the self-diagnostics will direct us toward what needs to be done. The engine should be running when you do these procedures.
"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"
So give that a try. There are more details on the printed pages of the manual which I can copy and postal mail to you so that you can hone in on the issue if the calibration doesn't self-correct your problem.
Roland
DJ in Texas wrote at 2009-07-11 01:05:54
Diagnostics results:
Cooldown test Passed.
Calibration/Diagnostics Failed with code:
7 flashes of the Intermittent Rear Wiper button (followed by)
1 flash of the Rear Wiper button
That sequence repeats until you Abort Test.
New symptom since performing testing is that the code for "Both Tests Failed" (Rear Wiper, Intermittent, Recirc & A/C lights all flashing simultaneously) is now staying on/flashing anytime the ignition is turned on. They all stop flashing after the requisite 15 minutes, and the A/C system continues to operate as I described initially...3 quadrants seemingly cooling efficiently, and the drivers quadrant dumping very hot air.
The temp. of the hot air increases as engine temp goes up so I'm guessing it's either pulling "fresh" air from the engine compartment somewhere or the drivers side (only) vents are open to the heater core perhaps? Is either of those possible?
Any further suggestions would be greatly appreciated. Thanks again
Hi DJ,
Thanks for the progress report. The 1-7 is telling you that the driver door actuator did not reach cold stop, which is consistent with the situation. The correction proceed as follows:
Check that the correct HVAC control module was used (moot at this point)
Using a voltmeter, chect at the temperature door actuating wiring connector, check pin 1 for battery voltage. Move the HVAC control from cold to the hot position, check pin 4 voltage it should change from 0.5 -1.5V to 3.5-4.5V. If voltage is OK go to step 3. If not OK, check for loose or corroded connector or shorted circuit and repair as necessary.
3. Remove actuator and check if the gear pins are in the correct track on cam or if they are binding. If OK go to step 4, if not repair as necessary
4. Check for binding of doors, if binding repair as necessary. If gears and door are OK replace actuator.
5. Once repairs are completed repeat the Calibration and Diagnostics test, and cooldown test. Repeating test is necessary to clear the fault codes.
To get to the blend door actuator for the driver, remove the lower left side steering column cover.*
Remove the ABS control module.
Remove the blend door actuator connector
Remove the blend door actuator.
As you look at the left side of the unit, there are three actuators. The upper actuator is the mode door, then of the two at the mid-level the left one is the driver and the right is the passenger blend door actuator.
*Remove screws holding parking brake release handle to instrument panel. Remove screw holding bottom of lower steerinh column cover to instrument panel. Remove screws holding right side of lower steering column cover to instrument panel. Disengage parking brake release cable from groove on end of handle. Disengage cable end pivot from handle. Lower the column covers out of the way.
Roland
