2000 Bonne Electrical Prob?

Hello, I Have A 2000 Bonneville Ssei Have Heater And Security Problems. First The Heater Started Blowing Luke Warm On One Side, And Cold On The Other. Then The Pass. Side Door Won't Lock With The Transmitter Which Messes Up The Security System. Any Thoughts? It's Getting Cold Here. Thanks So Much. Tk

Check your coolant level. If the coolant is low, that will cause your uneven heat. If it is low, and you see no external leaks, you may have an upper intake plenum leak (common issue on 96-up 3800-k motors). Failure to fix problem can result in severe engine damage due to coolant being drawn into the cylinder(s) and hydrolocking the engine. The door lock issue may be a bad door lock actuator.

I assume that you have Automatic Climate Control. There is a Driver Air Mix Actuator and a Passenger Air Mix Actuator. One of these actuators is either malfunctioning, or getting false control signal. You have a supercharged engine VIN 1, your engine is not susceptable to upper intake plenum faiure. As far as the passenger door lock, can you lock, unlock passenger door from drivers door? Can you lock, unlock passenger door locally from passenger door. Do all other functions in passenger door operate normally?