Re: [DML] A/C cycling switch

["Walter Coe" <Whalt@xxxx>]

Mike,

I checked out the technical article you referred to,
http://www.dmcnews.com/Techsection/aircondfancycle.html
and I think the author made some mistakes. I suggest to the list moderators
that the article be corrected.

I understand that the a/c compressor cycle time is supposed to be
approximately 7 seconds any time the engine RPM is well above idle. When
the author says that his manual recommends a cycling time of 45 to 90
seconds, I don't think he is referring to any of the three original DeLorean
manuals. He also says to adjust the pressure switch according to what is
recommended in the DeLorean manual. Again, I don't see where the manual
says a thing about adjusting this switch. The author doesn't mention this,
but the switch should not be tweaked unless you are absolutely sure that
your system has the correct pressures.

To contradict some of this, I have read DML posts from one guy who had
compressor cycle times of more than 40 seconds (I don't remember exactly)
but I think he was dealing with an R-134a conversion and not the OEM R-12.

Remember that observing the radiator fans is not a good indication of what
the a/c compressor is doing because the otterstat will switch the fans on
when the engine is warm enough. If you have a FanZilla installed, this will
further complicate things because the fans are now switched sequentially
with delay circuits.

One important point that the author did get right is to watch the polarity
on the circuit breakers. They are designed to have current travel through
them in only one direction. The markings are small and easy to overlook
since the breakers otherwise appear to be non-polarized.

Walt Tampa, FL