2004 chev suburban 1500 heater won't heat up front will in back blower works in front and back

Well antifreeze was a little low ,so filled it started car after let it warm up ,and now heat works in front also .Thanks anyway

Also, if you continue to have multi-zone disparity of cooling or heating issues with your 2004, don't immediately rush out and replace actuators, or have mechanics pull dashes, etc., in order to replace vent gates. There are commonly known issues that can occur with the logic panel in the automatic AC zone controls that can occur, particularly when the vehicle's battery is disconnected for a short period of time. The logic panel can be reset using one of these methods below. At some point an actuator motor may fail, but often is the case that it is actually just a 'logic' loop of the auto-system that needs resetting. This worked for me for a couple of years, before actually finally having to pull my dash to replace an actuator motor. https://www.youtube.com/watch?v=P_sNz9Ulzfo https://sparkys- answers.com/2011/08/hvac-actuator-recalibration-procedure.html