Pontiac Problems? Ask a Mechanic for Answers ASAP
Hi my name is ***** ***** I will be happy to help with this today.I need a little more info to assist better.
Can you hear a door or flap moving when switching from cold to hot at all in the dash area?
Are you ever able to get hot air at all (at idle or with engine revved up or heater/defrost switched to any position)?
Let me know so we can continue,thanks Pete.
Was the temperature actuator ever replaced at all?
O.k.,if the actuator was already replaced and the knob/control assembly was also replaced and the mechanic can get heat to work manually when this occurs and since you did find a broken plastic piece under the dash I suspect the temp door itself or part of the heater box the door attaches to has broken.This will keep the actuator from turning from cold to hot like this.In this case the heater box will either need removed and inspected and repaired or removed and replaced to correct this fault.
I have seen part of the heater box break before in the past with it needing replaced in most cases if it cannot be repaired and with all that has been done here already I suspect yours needs repaired or replaced.
If more help is needed, use the reply tab to continue our conversation. If no further assistance is needed, kindly rate my service.You can rate at any time and we can continue to work on your question as this will not close out your question.Keep in mind in some cases it can be difficult to fully diagnose or help repair your vehicle without seeing it and I work on delivering the best possible answer from what I see to work with.Thanks Pete.
O.k.,if the actuator was not replaced this is the most common cause for this fault here.I have had to replace the temp actuator several times for this issue.In fact if the mechanic can remove it he/she can move the temp door by hand and see if it manually switches from cold to hot and back and forth and if it does the actuator needs replaced.
I can see if I can find the procedure for replacement on this if you want just let me know.
O.k.,if it was changed then this leads to the heater box itself with either damage to the heater box or the heater box flap that moves from hot to cold.The heater box will need inspected to see if it can be repaired or replaced.
The blend door actuator is the temp actuator so it has already been replaced.This leads to the heater box itself at fault.