My heat is currently only blowing on my passenger side. The drivers side is blowing what feels like AC even though my AC doesn’t work. Why??

 

Try cycling your temp to max cold, wait a few seconds and go to max hot. There's a valve that controls flow of the coolant to the heater core near the firewall. Sometimes that valve gets stuck partially closed/open and doesn't allow coolant to fully enter the heater core. This happened to me when I had my TL years ago and cycling it a few times worked.

 

I think a year ago when my AC quit working my coolant was leaking from my heater control valve, is that possible? Could a broken or faulty valve cause this issue?

 

Yes. Not enough coolant is flowing through the heater core to fully produce heat for the cabin. Low coolant level or flow through the heater core will cause a loss of heating performance.

 

If one side is hot and the other isn't it's most likely your air mix motor. If you turn the driver side to max setting does it get warm? If you change the temps on the passenger side does the air temp change with it?