Climate Control Issue

[Void]

My 2002 SE seems to think it can decide when to blow hot or cold air... If I wiggle the temperature or speed nobes the heater will work.... Otherwise it just blows cold air. It will randomly stop working too and just blow cold then if I fiddle with the nobs long enough it starts working again. Any ideas???

[rixGAphx]

I don't *think* you have actual "Climate Control", with digitized thermometer, etc.

Rather, GA's have dumb ol' Heat/Vent/AC control knobs at the control panel.

These knobs actuate little valves that control the 'flow of vacuum' thru lines.
The lines go to the Heater/Evap fan box (under the dash) and to the Heater Valve (on the heater hose, under the hood).
At the Fan Box, the vac opens and closes little doors in the ductwork, which control whether fresh or recirculated air is heated, and which vents it blows out thru.
At the Htr Valve, the vac opens and closes a kind of water valve that allows more or less hot coolant from the engine to flow thru the heater core.

Now, sometimes the Contol Panel itself breaks or otherwise messes-up.
But usually, somebody dislodges a vac line or fitting while fartin' under the dash and installing a stereo or such.
Or, the could be a cut or other leak in the vac line going to the Htr Valve on the hoses (if the vac line touches the hot exhaust manifold, it can get a melt scar and hole).

Finally, the vac comes off the intake manifold.
There's a line that runs down toward the vacuum reservoir, which is a round black plastic grapefruit-sized and -shaped bottle under the battery.
Between the vac res and the engine, the vac line crosses open space where there's a 'T'; sometimes this 'T' comes loose, so vacuum isn't maintained.

Check all this vac stuff, I think your problem and solution will be found there.

Good luck.
-Rick

[MantaGreen97]

^It's still called climate control, Rick; it's just not "electronic" climate control...

For the 99+ I believe the temp door was controlled electronically (i.e. not by a cable like on the previous years). So you'll have to be sure the climate control panel has the proper voltage going to and from it, from the fuse panel to the temp door motor. Also be sure the temp door motor is operational... To do this you may have to jumper voltage to the motor, though I'm sure there has to be something that tells the motor what position it should be in...

A service manual would be of help here... What it sounds like is that the panel is messed up though. Either bad wiring or a bad HVAC climate control panel.