QuestionI have a 99 chevy p/u that appears to have a heating problem...The blower motor sounds and works fine but heat is luke warm...Truck seems to be at normal temp.....Could it be the damper door if so where is it located?
AnswerAnthony,
It could be a couple of things. The first question I pose to you is when was the last time you had your thermostat replaced. If the thermostat is not fully opening as it should, it will only let a trickle of the hot coolant into the heater core, thereby putting out lukewarm air into the cab.
And yes, the blend door is a possibility also. If it is not opening fully and allowing the proper amount of air to flow through the heater core, the little air that does get to go through will mix with the normal temp air and produce a lukewarm temp.
Now if your blend door is being the issue, that leads to a possible actuator being faulty (this opens and closes the door), a problem in your vaccuum system (tells the actuator when to open and close) or can even be traced back to your control head not sending the appropriate electrical signals to your vaccuum system. So I do not want to get into these aspects until you are able to narrow it down a bit more, simply because I would be typing for about 2 hours and just end up confusing the both of us.
You will find the blend door mounted to the blower housing under the passenger side dashboard. It is the door that seperates the heater core and the evaporator. If you have a vaccuum gun (needs to pull 8-12 psig)...... you will see a vaccuum line connected to the actuator on the door. Disconnect this line and hook the hose from your vaccuum gun to the actuator. When you squeeze the handle/trigger of the gun, you should see the door react. If it does, that narrows the issue down to either your Vaccuum control manifold, the vaccuum hoses, or your control head. If it does not react when you squeeze, then your actuator is the culprit and needs to be replaced. If you have the capabilities, try this, and if you still need help after the fact, I will be more than happy to assist.
Thank you for your question. If you found this response at all helpful, please remember to rate it. If I can do anything further now or in the future, please do not hesitate to ask. Thank you again, and good luck in everything.
