I just got my wife a 2000 GP GT and it seems like the car takes a long time to heat up. I just changed the dexi-cool and installed a new thermostat is there anything else to look for ?

Also... it has electronic dual climate control and the temp works great on the drivers side but the pass. side stays cold air blowing no matter how high i turn up the heat. Ive read it has to do with
a " blend door " Can i access it on the pass. side without tearing the dash apart ? Is there anything else to check ?

thanks for any help !!