A/C cutoff switches wiring diagram?

ab1Alex (@ab1) Melbourne
edited January 5 in General
hello again

I am finalising my upgraded a/c system on the 164 and am wondering if I should go a for a bit extra effort to put in a low pressure and high pressure cut off switch in the lines to prevent icing over the Evap and excessive pressure building to a point of causing a leak.

if I were to install these switches I'm a bit unsure how to go about it. the drier I have has a low cut off switch I believe however its been exposed to the atmosphere so ill just get a universal one for 20$ not going to pay 100+ for a volvo one.

im going to use atco air-o-crimp lines with the diy hoses kit from speedyairspares since I got quoted 500 to make up custom lines from an AC shop

cheers

Comments

  • Not trying to put you off making your own but all of the crimp your own A/C fittings I have personally seen people use have leaked (mostly braided A/C hose for show cars).
    Not sure what you would pay for a regas down in Vic but would suck if you went to all that trouble and had to get hoses made again plus regas the A/C.
    ab1Vee_Que
  • jamesincJames (@jamesinc) Oz Volvo Ice Fortress
    You fit the switch to the dryer. There would be a port on the dryer for it. You need to fit a switch, most a/c shops won't touch your car if you don't have one, it's some kind of regulatory requirement.
    ab1Vee_Que
  • youre not wrong about that. its one of my main concerns. the system that I proposed made by ATCO who make the beadlock fittings as well. so I have more confidence as it complies with regulations however im not completely sold.

    http://www.atcoproductsinc.com/products/air-o-crimp.

    @jamesinc I am yet to see a universal drier with the provision for one as the factory 240 one has
  • jamesincJames (@jamesinc) Oz Volvo Ice Fortress
    edited September 2018
    youre not wrong about that. its one of my main concerns. the system that I proposed made by ATCO who make the beadlock fittings as well. so I have more confidence as it complies with regulations however im not completely sold.

    http://www.atcoproductsinc.com/products/air-o-crimp.

    @jamesinc I am yet to see a universal drier with the provision for one as the factory 240 one has
    What dryer specifically do you have? I would just use these:


    I run both of these components in an R134a system and enjoy nice cold air

    Note that although the dryer is pictured with a pressure switch, I've found they usually don't have a pressure switch, and instead just have a blanking bolt that you remove and install your own switch in.
  • SUprBvEh.jpg

    thats what was attached to the Evap. but it hasn't been sealed for x amount of years so essentially useless.

    I don't really care what I use but would rather get something local Im over the 74 dollars postage for a 25$ item that barely weighs half a kg
  • jamesincJames (@jamesinc) Oz Volvo Ice Fortress
    @ab1 $27 shipping from Rock Auto, it's not always heaps expensive.

    You have the later receiver/dryer design, you could just buy a new one from Volvo dealership but I bet it'll cost a lot more than a generic one shipped from the USA.
    Vee_Que
  • Vee_QueVee_Que (@Vee_Que) South Eastern suburbs Melbourne.
    Its similar to a vn commodore filter fwiw.
  • Not always but still unnecessary if I can get one locally but there's a hassle in itself.
  • cmHSKtZh.jpg

    Like this @Vee_Que
  • My dad made his own hoses for his 1800E and ES and also his 240 I believe. Not sure what kind of crimper he used...I can find out. They look really professional (the hoses once done I mean). There’s several types available - could by direct from China! :)
    https://www.aliexpress.com/w/wholesale-ac-hose-crimping-tool.html
  • Pressure switch/s is a COMPLETE MUST. most switchs will have a low and high cut of point in the one switch. Low press cut out prevents your compressor seizing when line or gas leaks out. No gas no oil =seized compressor and high cut out is to prevent to high pressure building up and blowing hoses or components. The thermostat in your Evaporator box stops the evep freezing by turning on/off compressor at pre set temps. Theres lots of different A/c fittings and hose sizes just to make things harder
    ab1jamesinc
  • Ashdown ingrams they have pdf catalouge online and Australian they should be through Aus they sell all auto elect stuff and aircon hoses fittings and universal dryers switches ect.

    The acto system does work. Not that specific brand i have used but similar and same system and had succes. I prefer proper hydraulic crimps bead lock ect but i have proper crimper to do so and they weren't cheap. If you make all your own hoses which is no drama make sure you take it to a good Auto Electricial workshop to properly pressure test the system for leaks and to check the crimps and to regas it will save you in the long run. No leaks no regas for many years to come. Hope any of this helps
    ab1
  • @TL_V70 yes I agree I really do want to make use of the switch.

    the late 240 system does not implement a thermostat and my understanding is its operated through the switch on the drier/accumulator


    thanks for the ash down Ingrams - having a look at there website now

    ive grown skeptical of the atco system given theres hardly any evidence of it been used by people (good to know someone who can attest to it working). Im considering having a look down at the wreckers to see if I can find some hoses off a vehicle that will match - given its a b30 a lot longer than b230 so the firewall hoses are unlikely to fit. maybe a 960 hoses may line up or s80

    other option is to measure up all the hoses and take them to an auto electrician to make use of their beadlock crimper thus hopefully significantly reducing the cost.
  • ab1Alex (@ab1) Melbourne
    edited January 5
    i ended up getting enzed to make the hoses before realsiing how much they charged.... oh well theyre done and done professionally so im expecting no leaks hopefully.

    Im on to the wiring as one of the final steps but cant seem to find a diagram of how to wire in a high side and low side cut off/pressure switches. would anyone have a 240/740/940 wiring diagram with the gm style system in it. @jamesinc :+1: would you have any ideas on this one

    i have read about trinary/binary switches would allow the ac fan to turn off when the pressures in the system are not high enough to require extra airflow (this would be ideal however im not sure how much complexity this adds to the wiring)

    cheers
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