There is a little vacuum line/tube right next to the 2 hoses that go into the heater core in the engine bay, and it is broke in half.

Would this be the cause of my hvac controller being inop? it is on default(defroster), i picked up some heat shrink and am going to repair it that way since the broken tube is way to small to splice in a new piece

Thanks

Rich

Yes. That tub routs vacuum to the heater controls. Without it they will default to defrost.

Do you think the heat shrink will do the trick to repair it?

I used electric tape for a year with no problem so heat shank should work