97 Lesabre Limited Climate Control Issue?

[mmclean27]

I have got a couple issues with my 97 Lesabre Limited. First off the heater seems to have issues. It will turn on then in will seem to randomly turn off then on again. At some times it seems to coincide with my acceleration but not enough to say for sure. Also my AC is not working properly. No cold air being blown just the fan and it too seems to have the same symptoms as the heater. Now the reason I feel it could possibly be the Climate Control Unit is because the numbers on the unit (The degress farenheit) on the Unit are dimly lit unless you tap on them. The vehicle also has an issue with a hesitation when the vehicle is warm as I am going up a hill at about 40-55 Mph or so. Not sure if it could be related to the before mentioned issues with the climate. Sorry for the long post and thanks in advance.

[imidazol97]

Originally Posted by mmclean27

I have got a couple issues with my 97 Lesabre Limited. First off the heater seems to have issues. It will turn on then in will seem to randomly turn off then on again. At some times it seems to coincide with my acceleration but not enough to say for sure. Also my AC is not working properly. No cold air being blown just the fan and it too seems to have the same symptoms as the heater. Now the reason I feel it could possibly be the Climate Control Unit is because the numbers on the unit (The degress farenheit) on the Unit are dimly lit unless you tap on them. The vehicle also has an issue with a hesitation when the vehicle is warm as I am going up a hill at about 40-55 Mph or so. Not sure if it could be related to the before mentioned issues with the climate. Sorry for the long post and thanks in advance.

When you say the heater will turn on and off, is the blower changing speed? Or Is the air direction changing from dash or floor to the defroster?

Loss of vacuum causes the air path to go to the defroster for safety reasons so that in event of a problem you'll always have the ability to clear the windshield for vision.

Your can may have a cracked vacuum line near the engine. That causes a leakage but vacuum still exists to operate the internal heater parts until you step on the gas and the vacuum drops.

You might have a cracked reservoir tank that's supposed to "store" vacuum for when the engine is accelerating. There's a one-way valve between the vacuum tank and the engine. The vacuum tank is behind the headlights in front of the right front wheel. Lie on the ground and look up. It has one line going to it. If you run the motor, turn it off, then go there and pull the line you should get a whoosh as air rushes in to fill the lower pressure there.

You might have a problem with the heater/AC control which uses vacuum lines to operate 3 or 4 valves to make air go the direction you've chosen. There are articles about the connector in the corner of the controller box (programmer) that is soft plastic and sucks closed with age. That's the AC line that closes meaning the dash vents won't force the air out of them. Usually the floor vents and defroster settings seem to work okay. The bad plastic junction can be bypassed with little lines connecting the inside and outside parts.

[C man]

Had the same issue. My climate control unit started to blank out, or not display the numbers all the way. But it only seemed to do it on acceleration at first but it got progressively worse and just started to do it at random times. I initial thought it was a vaccum leak but it turned out to be the climate control unit. Had to get one from the junkyard from a 98' park avenue. Only negative thing is that the lights for the control buttons don't work. But for $12 I can't complain. Dealership price for a new climate control unit is $900!!

[mmclean27]

Went and got another Control unit from the junk yard yesterday. I also recharged the system with some freon. Its blowing cooler than before and the new Control Unit seems to be working properly ie. turning on when asked to and all the numbers are well lit. Well see how long the freon holds hopefully there is not a huge leak. Thanks for the help and will post the results.