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Followup To
Question -
I have a 1996 Buick le sabre 3.8 when you turn the heat on, either vent or defrost you get no warm or hot air no matter the temperature setting. I have noticed with the heat on not defrost that the ac compressor is on. I have full control of the fan, vent, floor & defrost just can't get hot air. I have replaced the water pump, flushed the system both upper & lower radiator hoses are equal in temperature. sometimes if you accelerate really fast
(jump on it) you will get heat untill you shut the car off.
Answer -
OK, First I need to know the past repair history of the vehicle. I mean everything that has been worked on or replaced from the engine to a light bulb.
What was the LAST repair that was done to this vehicle prior to this problem. ?.
Most problems that occur days or weeks after a repair was made anywhere on the vehicle are in most cases traced back to the area of where previous work was performed. A vacuum line or electrical connector may have accidentally been cracked, broken or loosened during the last repair.
Most vehicles are designed to deliver hot air into the passengers compartment via the air vents when vacuum has been lost such as when you shut off the engine. This is a DEFAULT mode because GM was, If not mistaken sued many many yaers ago when some people were out in the winter and their car stopped and at that particular time there was no DEFAULT heat from the air vents at that time and the people froze to death. The suit was brought on whereas it was stated by the lawyers in that if the hot air DEFAULT was manufacturerd to provide the last bit of heat from the air vents from the engine, The people may have survived. This is why in later vehicles you have DEFAULT hot air from the vents when the engine stops for a few hours until the engine eventually gets cold.
This was just something I heard many years ago, But it makes sense.
Therefore, since when you accelerate hard this drops the available vacuum from the engine thus causing hot air to be expeled from the vents.
So, This would indicate and it is most likely in that you have a vacuum line leak and or restriction within the A/C-Heater vacuum line from the engine and or within the A/C-Heat system.
You need to physically inspect your vacuum lines on the engine and on the vacuum controlled devices under the dash.
Let me know what you find.
autohelp
This is in response to your request for more repair history. the only thing that was done prior to this problem was plugs & wires. also why does the AC compressor come on while the heat is on it didn't use to do that.
AnswerOK, I get up to 50 questions per day on the different boards that I am on like this one and is it hard to keep track of who needs what.
How long AFTER when the plugs and wires were replaced did this problem start to occur. ?.
There is a strong possibility due to the tight fit on the engine and the difficulty at getting to some of the spark plugs and or wires that a vacuum line or electrical connector could have been accidently knocked loose and or siad vacuum line and or electrical connector may have finally came off it's connector thus causing your problem.
You need to take a LONG GOOD look in the engine compartment and look for just this kind of thing.
When the defroster is selected the A/C compressor will engage. On most of the newer vehicles that have AUTOMATIC DIGITAL TEMPERATURE CONTROL on the vehicle the A/C compressor can come on at any time so as to maintain the selected electronic temperature control within the passengers compartment.
I don't have a 1996 Buick service manual at my disposal so I can only rely on what I have seen as to this type of problem over the years.
The only other possibility, Without actually doing any hands on diagnostic procedures would be that there is a fault within the A/C-Heater control module or within any of the climatic control components. You are going to have to obtain a Buick repair manual and perform the diagnostics to identify and correct your fault.
I wish I could tell you exactly what part has failed, But it is just impossible without doing the diagnostic procedures and just guessing and replacing parts can get VERY expensive.
autohelp
