heater blows on 2003 Nissan Altima

the heater blows cool or cold at idle, is it true the temp sensor in the front of the car can cause this. if possible is there somewhere i can find the info on how the system works without buying a manual at this time.

1 answer
It is unlikely that the ambient temp sensor would cause this problem. Check your coolant level. Low coolant will cause inefficient operation of the heating system because the heater core has little or nothing flowing through it so no heat gets transferred to the passenger compartment. Does your heater work normally at higher engine speeds?