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        General >> Problems >> AC pressure switch
        
(Message started by: kiloWATT on Jul 2^nd, 2011, 9:38pm)

Title: AC pressure switch
Post by kiloWATT on Jul 2^nd, 2011, 9:38pm

hi,

i've installed Scorpio's AC system into my 1981 VW Santana, everything is kind off ok, but could anybody tell me how does pressure switch works?
i know that one pair of connectors works as a safety feature for hi(~30bar) and low(~2bar) pressure (turns off the clutch of the AC compresor), but what about second pair of connectors? i just know that it controls the fan..but how? by readings of system presure? by temperature of oil in system?

if anybody knows how that sensor works i'd be very glad, thanks. :)

Title: Re: AC pressure switch
Post by gozz on Jul 2^nd, 2011, 11:19pm

The pressure valve is linked to the PCM,look at the wiring diagrams under 'how to do things',Snoopy has put them up there for us all.You will be able to see where your problem lies.

Title: Re: AC pressure switch
Post by Tompion on Jul 2^nd, 2011, 11:39pm

on 07/02/11 at 21:38:14, kiloWATT wrote:

hi,

i just know that it controls the fan..but how? by readings of system presure? by temperature of oil in system?

if anybody knows how that sensor works i'd be very glad, thanks. :)

As Gozz says it's controlled via the PCM. I haven't looked to see exactly how it happens but in essence the moment the compressor clutch engages the fans come on low. When the clutch disengages the fans go off after a few seconds.

Title: Re: AC pressure switch
Post by kiloWATT on Jul 3^rd, 2011, 4:06pm

thanks, i found wha i was looking for. if anyone interested the pressure switch turns the fan on "hi" just when the pressure is high. i'mn not sure if anything else can turn it on on "hi".