Pontiac Repair: Heating unit issues..., manula, ambient temp

Question
So upfront, I am completely automotive-ly challenged. Im going to explain as best as I can without confusing you. Ha

Okay, so I have a 97 Bonneville SE, V6, 3800 engine, just crossed 150k miles.

The problem(s) is/are, The air in my car will only blow from the window vents. I can change the air flow on the control panel, and it will display where its supposed to blow from, but physically it will only come out of the window vents in front of the windshield.
Also, it will only blow cold air, I cant figure out why it wont blow heat. I think it has something to do with the fact that my temperature display only reads 176 degrees outside temp. at all times.
So I am not sure if this all stems from the same issue or if they are separate.

Run down
1. Air only blows from windshield vents
2. Only cold air will blow
3. Temperature only read 176 degrees

Please help as best you can, im completely at my wits end with this car.
Feel free to ask any additional questions to better solidify your hypothesis.

Please and Thank you,
Willie E.

Answer
Hey Willie;

i think you have a few issues here. The fact that the ambient temp always shows that temp is a big part of your issues. the auto HVAC uses tem sensors to base what the system should do cool/heat etc.... I would start by trying a new ambient temp sensor and I would also get the car scanned for codes and see what is stored in what modules. You may have a actuator that is not working properly and it may have set a code. Those older cars the Auto HVAC systems were a bear to try to diagnose the dignostic in the service manula is horrible for those older systems. once you replace the temp sensor disconnect the battery and then drive the car it needs to see vehicle spped to update the ambinet temp sensor. So I would start that and then see what happens and see what codes you have stored.... Good luck :)