Past couple says it seems to work fine....then blow colder...then blow warm again and back to colder...quite weird...any idea why?

 

Thermostat, heater core, coolant temp sensor?

 

Have you removed the cabin temperature sensor from the list of possible culprits by testing the system in manual mode to see if the problem still exists?

Might check your coolant levels as well. Low engine coolant, or air trapped in the system might be causing the problem.

 

Have you changed your coolant recently? I did a few days ago and i have air trapped in the system which causes mine to do that. Just bleed the coolant system. Its free and easy so i would try that first. Hope this helps.

 

Have not done anything with coolent. I will check it out tomorrow...how do u bleed the coolent system?

thanks