I have been having some heating issues.It hasnt been pumping out very much heat.My engine is running normal temps,I also changed thermostats.I am thinking,that maybe a door to cover the heater core isnt opening,???I am wondering if there is a solenoid or relay that you would change?the engine is running normal.I was thinking that if it was a vacum line disconnected it would effect how the engine is running.I am wondering if I have to disconnect the passenger airbag if I have to take the heater unit apart and where I do that? any info would be appreciated ,thanks

Your heater core could be plugged. How does your coolant look? Is it low, or is there sludge in it? If your coolant is full, check your heater hoses with the engine at operating temp. They should both be hot. One may be slightly hotter than the other. If one is hot and one is cold you probably have some sort of blockage. If you have blockage, you can take the heater hoses off and flush the heater core with a garden hose.