Lorenfb

"The setting motor is on the side of the HVAC box inside the center console"

This servo motor & switch assembly is key to proper climate control functionality,
as it moves the mixing flap and controls vacuum solenoids, e.g. the water valve.
Many assume that the dash climate control unit (CCU) is all there is to the HVAC system,
when if fact it's only one many system elements and generally never the problem
with the exception of the compressor not working. The CCU is typically assumed
the problem and replaced initially when HVAC doesn't function, which generally
wastes time and money for both the car owner and the CCU supplier.

FiveElements

anyone have the setting motor & switch assembly part number? Can this unit be found or rebuild anywhere?

Alan

Why assume there is a problem with it.... I wouldn't...

If you can get full hot and cold and full cold - evaluate if it moves full range between those modes - if yes - I'd just assume it was working properly and investigate the sensor loop instead - its a 95% chance thats where the problem lies based on the symptoms you describe.

Don't chase phantoms unless they are proved real... The setting motors are normally very reliable.

Alan

Alan

The head unit is much more often a problem than the setting motor.. (which is generally quite reliable).

The setting motor unit does not control most of the air distribution flaps and controls the water valve only on a few model years and not exclusively even then....

Start with the sensor loop - you'd have to be crazy to start anywhere else....

Alan

Lorenfb

"The head unit is much more often a problem than the setting motor.."

Only with regard to the compressor not working! Neither the CCU nor the
servo unit is the usual problem.

FiveElements

Excuse my ignorance... the head unit is the temp slider on the dash board and the resistance of that slider? I'm reading as many threads on this as I can, but it seems to be a bit complicated. I'll check back with more input on what I find and note some specific ohm readings I get on all sensors. This problem is likely not the setting motor, it does move, I do get cold air and hot air. Just no consistent "clicking" of the vacuum valves to control temp. It works some days and other days not, so it seems to be either a loose connector or a intermittent failure of a sensor if that even possible.

FiveElements

Ok... after lots of testing I seemed to have found the problem. If the flex hose comes off the alternator, that seems to effect the outside temp sensor enough to give intermittent "all hot" heater problems when the temp slider is off of 65º. I repaired and re-attached the cooling flex hose that goes from the alternator and not the heater and AC work perfectly.

Lorenfb

"If the flex hose comes off the alternator, that seems to effect the outside temp sensor enough to give intermittent "all hot" heater problems when the temp slider is off of 65º."

That sensor should not be that close to the 'edge', i.e. most likely one of the
sensors is out of spec or a bad connection in the sensors 'loop'.

FiveElements

Strange that once I fixed and reconnected the cooling flex tubing at the alternator, all worked again. I'm now thinking there is a poor connected to the outside temp sensor. Everything works now with no problems. First time in 2 years there has been no problems.