This week I replaced the blower motor and the resistor on my 2004 Titan because the motor was making a constant clicking sound. After I replaced both parts my HVAC system was working great. Today I took it into the dealership for the ECM relay recall and the aux fan from a while back. They replaced my aux fan and motor because it was bad and not even working and replaced the ECM relay. Tonight me and the wife got out to run to some places and I turned on the heater because it was cold. Now when we turn the temp control knob to either hot or cold it makes a creaking sound and if you turn it to the cold side you will get a clicking sound from the farthest left side behind the dash. The position control knob is also making noise now also, kinda like a motor that's straining. The system wasn't doing this yesterday or this morning before I took the truck in. My question is, could have replacing the ECM relay had any kind of affect on or done anything to my HVAC system or do you think it's just 6 year old parts failing?