I replaced the battery in my 1998 Chevy Blazer and now I don't have heat. I have taken out the RDO fuses (which was recommended to me), put them back in, started my Blazer and there was heat for about 20 seconds, then it turned cold. I don't understand why replacing the battery would effect the heating. What can I do?? What do I need to reset?? Thank you for any help you can give.
The problem is the blend door actuator. Its is located behind hte glove box. (as far up and to the left as you get get with your hand). The gear inside the motor will crack if it is overdriven. As far as the re calibration, pull the rdo fuse(s). wait about 30 sec. replace fuse(s) turn car to run wait for 40 sec or so. you should be able to get a flashlight and watch the motor turn back and forth. turn key off. you should have heat. if not, pull the motor out. very easy just two screws. open the motor can check large gear for cracks
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I have a 1998 Chevy Blazer, 4.3 ltr... in the fuse box i am trying to locate the fuse for the dash board lights(light behing the speedometer and the radio lights and the lights that illimunita the heat/ac control kmobs... need help,any ideas and or good sites to go to ? thanks need info asap...its jan 25 2011 5:15 est...
I've been dealing with this for a couple of weeks now on my 98 blazer. I have access to schematics and a scan tool which makes it a little easier. My experience has been with the automatic climate control system. I don't know very much about the manual control. There are several possible problems. The most likely, is that one of the gears in the blend door actuator is cracked. Therefore, the blend door is stuck in one position. The actuator CAN be accessed through the glove box but it is tight. On the left hand side you will see a vacuum controlled lever. That is for the defrost (if you turn the truck on and switch the vent position switch back and forth you will see it move). The blend door actuator is behind that so its easier to remove that vacuum diaphragm to gain access. The overdrive problem mentioned earlier could also be a problem. To reset this, turn the truck off, remove the RDO fuse for 30 seconds, replace the fuse, then turn the key to the run position. This will start a calibration cycle to reteach the computer where the maximum and minimum rotation points are so that it doesn't overdrive. If, after doing this procedure, the hvac system cycles back and forth from heat to cool there is probably a code set in the Climate control module and it may be time to get a dealer with a scan tool involved. On my truck and at least one other truck I have found out about, the control module is unable to sense the location of the actuator door (that is what causes it to "overdrive"). You can verify if your module is over driving by removing the blend door actuator but leaving the electrical connector on. Turn the truck on, cycle to heat. The visible gear should rotate one direction then stop. Cycle to cool. The gear should rotate the other way and then stop. If it doesn't stop there may be something wrong with the control module. Good luck and hope this helps. Keep me posted, be glad to help. You can buy the part at Auto Zone or you can go to the Salvage Yard and pick one up for $20.00 and you can get a better understanding to how to remove the old one from a salvage Bravada, blazer, or jimmy of the same years.
Replacing the battery has no effect on the heating system. Do U have a temp gauge to know if the engine is getting up to temp? and then the heater should put out heat. If it doesn't then U should look at replacing the thermostat