Pontiac Repair: climate control, vacuum tee, vacuum leak

Question
96 bonneville with afew issues.the heat only blows in the defrost reguardless what position selector switch is in. also ,the hot air blows inconsistent with each start up. i shut the car to refuel then started it back up only to have cold air blow.  

Answer
Hi Mark:

I'm going to assume you have auot climate control on this car? as far as the heat only out the defrost I would say you have  a vacuum leak in the ssytem going to the HVAC system more then likley at the engine a vacuum line split or fell off back by where the brake booster hose atatches to the engine there is a vacuum tee there and the hose has a tendency to splait cark and or come off there. as for the temp not working with out the use of a scan tool and seeing what codes are set if any in the system I can't tell you what the issue is there. you could have a temp sensor in the car that is bad causing this. the controler for the hvac could be bad or a bad actuator for the temp door. It' would just be a guess. a lot of the big box auto parts stores will scan the cars for codes for free and if so you at least have a starting piont to go from... good luck :)