I have a 2000 tahoe with a heater problem.... any information will help. the blower is good, changed thermostat, the heater only blows out warm air that will not keep us warm in winter. I was told it is some door in the heater ac switch but I have no clue how to get to it. Thanks for any suggestions.

 

check and see if the temp blend door actuator is moving. remove the hush panel at the passenger footwell area and watch and listen for movement and sound from the actuator when the temperture **** is changed.

The best way to diag this is to retrieve and codes that may have set. You will need a full function scan tool that reads body codes. Without the tool, its all a guess.

 

b4richards Welcome to the forum...

You might want to try the re-calibration procedure to see if it resolves the issue, I know this works for the new body style not sure if it applies to the previous body style, but its worth a try...


Important: Do not adjust any controls on the HVAC control module while the HVAC control module is self-calibrating. If interrupted, improper HVAC performance will result.

Place the ignition switch to the OFF position.
Remove the HVAC/ECAS fuse for a minimum of 10 seconds.
Install the HVAC/ECAS fuse.
Start the vehicle.
Wait 40 seconds for the HVAC control module to self-calibrate.

 

My 2000 silverado had a similar problem. The heater core was stopped up. I unhooked the lined and ran the garden hose thru it backward and it corrected my problem. took 10 minutes