Nissan Repair: 95 Nissan Altima heat not working, nissan altima, heater control valve

Question
I have an 95 Nissan Altima and I just replaced the alternator yesterday. And today when I started the car and turned on the heat, only cold air came. I followed the hoses and touched both. one is hot and one is cold.the thermostat control inside is on middle between c and h. could I have a bad heater core? Or if not, How do I bleed the line? thank you in advance.

Answer
Hi Sandy,

You have a heater control valve that is run by vaccuum. There is a good chance that while the alternator was replaced, it came off. Follw the heater hose until you find an in line connection with a vaccuum hose nipple on it. First of all, check to see if there is a hose attached. If not, you have found the culprit. Locate the hose, which should be around somewhere and reconnect it. Ensure you have suction on that hose while the car is running.

If there is suction, and still no heat,

Try removing it and reconnect with a straight pipe. If that works, then your heater valve needs to be replaced.

Hope this helps -
aloha
calvin