Help. I replaced the battery in my Tahoe. Now the heat doesn't work--front or rear. Here is all I have done:
-removed battery cables, key in run position,waited 5 min replaced cables--heat worked for 1 day
-checked blend door--it worked.
-disconnected battery-touched cables together for 10 seconds
-disconnected actuator--heat worked, reconnected -no heat
-left actuator disconnected, heat worked but weird smell in cabin almost like the smell when a car overheats--also heat blew at 60 degrees hotter than when thermostat on 88 degrees but I had heat
-next morning--no heat
-checked all fuses
-checked hoses to firewall-both hot

Help-I don't know what else to try.

-disconnected battery again--still no heat

 

Try this. Start vehicle. Turn passenger side to max heat and drivers to max cold. Let run for a minute then turn off ignition. Start engine and reverse settings. Stop engine. Restart and set to normal settings. Worked for me. May have to do it a couple of times.