I could use some advice on a climate control problem. All thoughts
Symptom: the system, fundamentally, is operational as intended…it cools,
it heats, the blowers self-adjust, etc. However, quite often (75% of the
time?) it just doesn’t know when to stop. For instance, if cooling is called
for the system will keep cooling long after the desired temperature is
reached. Similarly, when heat is called for, the system just keeps pumping
out heat until my toes roast. In either case only an adjustment of the temp
knob will reverse the action…and sometimes an exaggerated adjustment is
required. From time-to-time I get cold air when I expect warm air. But I
never get warm air when I expect cold.
The only pattern I can discern is this: when I jump into the car and drive
off, the system will stabilize and behaves fine UNTIL it decides the first
adjustment is called for. As soon as it self-adjusts ONCE, the undesired
behavior begins and will continue.
I did a couple of quick tests this morning. Both the ambient temp sensor and
in-car sensors are skewed, both “thinking” the cabin is colder than it
really is. This would perhaps explain why the system would want to pump out
heat for an extended period of time, but wouldn’t explain the
reverse—pumping out cold air long after the desired temperature has been
What I have not tested yet…silly me…is the resistance of the
temperature control itself. I will do that today. I have thought of
adjusting the potentiometer on the amplifier but have not done so, as it
seems to me that doing so would only address an issue where the system
over-cools or over-heats—but not both.
Thoughts so far?
I have swapped amplifiers, by the way, and it made no difference.
Longview, Washington USA
1987 Ser III XJ6
1988 XJS V12===================================================
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