AC Hot and Cold Question. Winner gets a Starbucks Coffee.
#1
09-29-2007, 10:13 PM
AC Hot and Cold Question. Winner gets a Starbucks Coffee.
Hi, I have a 98 Blazer with Auto Climate Control. Recently after a dead battery change my HVAC started blowing Hot air for 10sec and then Cold air for 10secs and just keeps switching back and forth. Finally the Gear in the Blend Motor gave out and it was just stuck on Hot all the time no matter if I switched on AC or not. So.....I installed a New Blend Motor and now it back to blowing Hot air 10secs and then Cold air for 10secs. If I turn the heat/air to off position, I can feel the Blend Motor still switching back and forth. I tried disconnecting the negative side of the Battery for 3min to see if that would reset the Climate Control system, No Luck. I tried pulling the RTO/BATT fuse for 2mins and then immediately switching the ignition on to see if that would reset the Climate Control, No Luck. So I'm not sure if its a Reset Problem or Sensor or Control Valve Problem.
Now, I'm thinking maybe its a Bad Inside Ambient Temperature Sensor (which islocated on the dash)or its a bad Temperature Contol **** on the dash???If someone can help me resolve this, I'll send you a Starbucks Card for a free coffee.
Thanks ....Rocket
Now, I'm thinking maybe its a Bad Inside Ambient Temperature Sensor (which islocated on the dash)or its a bad Temperature Contol **** on the dash???If someone can help me resolve this, I'll send you a Starbucks Card for a free coffee.
Thanks ....Rocket
#2
09-30-2007, 07:51 AM
RE: AC Hot and Cold Question. Winner gets a Starbucks Coffee.
Well, seems like you've already tried this, but here it is again:
And just note that the engine must not be started, just turn the key to the run position.
Other than that, a scan tool capable of accessing the ECC module is required to check for codes and to complete the functional testing...
Re-Calibrating Actuators After Power Loss
Calibration of the Electronic Climate Control (ECC) module occurs whenever B+ is removed and then restored to the ECC module. During this calibration process the ECC module will automatically command the temperature door to the full HEAT position and then to full COLD position. The ECC module records both the minimum and maximum door positions and uses this data, which is in counts, to determine temperature door settings based on customer selected temperature settings.
IMPORTANT: Do not select or use the scan tool HVAC menu during the ECC module calibration period or the ECC module will not calibrate properly.
If the ECC module has been interrupted by scan tool operation the temperature door will become inoperative. If this should occur then:
1. Turn the ignition switch to the OFF position.
2. Disconnect the scan tool from the Data Link Connector (DLC) .
3. Remove the RDO BATT fuse for 10 seconds and then reinstall the fuse.
4. Place the ignition switch in the RUN position and wait 40 seconds for the ECC module to initialize.
Calibration of the Electronic Climate Control (ECC) module occurs whenever B+ is removed and then restored to the ECC module. During this calibration process the ECC module will automatically command the temperature door to the full HEAT position and then to full COLD position. The ECC module records both the minimum and maximum door positions and uses this data, which is in counts, to determine temperature door settings based on customer selected temperature settings.
IMPORTANT: Do not select or use the scan tool HVAC menu during the ECC module calibration period or the ECC module will not calibrate properly.
If the ECC module has been interrupted by scan tool operation the temperature door will become inoperative. If this should occur then:
1. Turn the ignition switch to the OFF position.
2. Disconnect the scan tool from the Data Link Connector (DLC) .
3. Remove the RDO BATT fuse for 10 seconds and then reinstall the fuse.
4. Place the ignition switch in the RUN position and wait 40 seconds for the ECC module to initialize.
Other than that, a scan tool capable of accessing the ECC module is required to check for codes and to complete the functional testing...
#3
10-01-2007, 05:15 AM
RE: AC Hot and Cold Question. Winner gets a Starbucks Coffee.
Hmmmm? I tried the RTO/BATT several times. Pulled fuse for about 30secs, put back in, turned ignition to Run position for about 2mins. Started car and I can hear the Blend Motor still cycling back and forth even whenFan Motoris in theoff position. Even with all Climate Controls turned to the Off position, I can still hear and feel the motor cycling back and forth. Do you think I need to have a Special Scan download done to the computer? I really hate to take it to the dealership.
Thanks ...Rocket
Thanks ...Rocket
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