Heater blower not working on 2005 Envoy

I would check the blower motor first, make sure it is getting power.

replace the switch its self.. you can search ebay motors under electrical and find one easily.. also they remove easily and just plug in the back..

does the car have automatic climate control?

Check whether you might have bad connection or contact,or e ven bad switch.

To troubleshoot this types of problem,click the link below :----http://howtobyme.blogspot.in/2012/02/heater-blows-only-from-defrost.html
--------Go through the procedure to confirm the issue.

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Engine Overheats and heater blowing cold?

http://howtobyme.blogspot.com/2011/11/engine-overheats-and-heater-blowing.html

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Heat blows cold on drivers side and hot on passenger side?

http://schematicsdiagram.blogspot.com/2011/12/heat-blows-cold-on-drivers-side-and-hot.html

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No heat on car? http://technoanswers.blogspot.in/2012/02/no-heat-on-oldsmobile-silhouette.html

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Heater blows intermittently and temp gauge goes erratic? http://technoanswers.blogspot.com/2012/01/heater-blows-intermittently-and-temp.html------------Heater blows cold? http://schematicsdiagram.blogspot.in/2012/02/heater-blows-cold.html
---------Car heater blowing warm, but not hot air? http://schematicsdiagram.blogspot.com/2011/12/car-heater-blowing-warm-but-not-hot-air.html-------- Heater/AC blower motor not working?

http://technoanswers.blogspot.in/2012/02/heaterac-blower-motor-not-working-on.html

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A/C, heater, defroster fan, not working? http://technoanswers.blogspot.in/2012/02/ac-heater-defroster-fan-not-working.html Heater problem? http://technoanswers.blogspot.in/2012/02/heater-problem-on-isuzu-trooper.html---------

This will help.Thanks.

REPLACE THERMOSTAT.IF ALREADY DONE.CHECK HEATER BLOWER MOTOR SEE IF POWER GOING TO HEATER BLOWER MOTOR.IF YES BLOWER MOTOR BAD.IF NO POWER GOING TO BLOWER MOTOR CHECK AC AND HEATER CONTROL FUSE AND CHECK BLOWER MOTOR FUSE AND RELAY IF ALL IS GOOD CHECK SEE IF POWER GOING TO AC AND HEATER CONTROL SWITCH IF YES THE AC AND HEATER CONTROL SWITCH COULD BE BAD.

CHECK SEE IF POWER GOING TO BLOWER MOTOR IF YES BLOWER MOTOR EITHER BAD OR HAS POOR GROUND SHORT IN WIRING CONNECTOR GOING TO BLOWER MOTOR AND RESISTOR.IF NO POWER GOING TO BLOWER MOTOR CHECK BLOWER MOTOR 30 AMP FUSE OR RELAY.IF BLOWER MOTOR OKAY AND FUSE RELAY OKAY THE AC AND HEATER CONTROL SWITCH COULD BE BAD.

how do i fix my ac/ heater they both wont work not even defrost it use to work only on selection number 5 now it dont work at all we just put a new blower in it today and it still wont come on

Having to increase speed to get any heat means that your coolant may be low, as far as only 1 speed, the switch for the heater may not be working properly

all speeds??? could be resistor pack or the blower itself. rap on the blowe and see if it tries to run, if it does, replace it.