1998 Q45 Climate Control stays cold even at 83

[valq45man]

Hello,

My 98 Q45 Climate Control system seems not be working properly. Even when I put the temp at 83 it is still blowing cold air. Could this be the temp sensor ? Or the computer itself ?

Thanks for the help !

[qship96]

system will blow cold air until actual in-car temp is at or below where you have system set to{83 in your case}

[valq45man]

It says blowing cold the entire time - even hours when I'm on a road trip. That's why I was asking about the temp sensor inside the car - could that be bad ? It will blow hot only when I put it at 85.

[qship96]

if you are set at 83,is the interior temp dropping much below 83,or is it blowing cold air trying to maintain the 83 degree setpoint? I would assume it is hot in texas and the ac must have to blow cold air to reach and maintain your 83 degree setpoint.

[valq45man]

I think it is much cooler than 83 degrees inside the car. Outside temp is probably about 85-88 right now. But I would think inside the car is closer to 70 or so. If I put my hand on the center vents - the air temp feels like it is coming out as if the setting was at 65.

[qship96]

if that is truly the case,then yes,you have a problem! confirm the in car temp with a thermometer

[valq45man]

Isn't the temp sensor just under the steering column ? I'm wondering if that is not working at all and that's why it doesn't adjust the setting correctly ? Is that a dealer item only ?

Thanks for your help.

[qship96]

You can run a diagnostic check of every HVAC sensor and air control system thru the a/c display with no tools or disassembly of anything in about 3 minutes! look for procedure in service manual,or search this site for directions-I know it is posted here somewhere

[valq45man]

Thanks very much... I will look for that diagnostic test procedure. That sounds like a good place to start. Hopefully someone will have that posted here somewhere.

[96Qowner]

1996 or 1998?

Here's the HVAC diagnostic procedure for the 96, starting on page HA-22::

Heating & Air Conditioner Section of 1996 Q45 FSM

Here's the 1998, page HA-21:

Heating & Air Conditioner Section of 1998 Q45 FSM

[valq45man]

Thanks again for your help. First off - I didn't realize the in car sensor is on the upper dash by the defroster vents. So when I'm driving it gets direct sunlight !! The diagnostic tests shows that it thinks the temp is very high so I guess it is working properly. However the diagnostic tests also shows you how to "adjust" the temp by up to 6 degrees. So after I did that it seems to be working much better !

Thanks again...Val