Connect with us

Car A/C circuit, want to make manual control as it does not work properly.

Discussion in 'General Electronics Discussion' started by apples, Aug 29, 2012.

Scroll to continue with content
  1. apples


    Jul 1, 2012
    The A/C system in the car is as dodgey as a second hand lawn mower.

    I would like to bypass the computer that controls it. I suspect a fault in the computer or a corroded, loose, wire or somewhere. I have also lost the central locking, the horn has blown a fuse, and the blower fan for the heater /ac has a mind of its own, turning on and off when it feels like it.

    I figure I can rewire the AC compressor into a new circuit that will miss the computer. The one thing I am unsure about is the pressure switch that is on the top of the filter/dryer.

    It detects if the pressure gets to high and then breaks the circuit to stop the compressor from pumping so the system does not blow up. Then again when the pressure lowers down it allows the compressor to start again.

    I do not know what to do to detect when it needs to go on and off?
  2. mrmodify


    Feb 13, 2010
    Need a little more info.

    Evening Apples,

    First what is the year make and brand of car.

    Usually the switch on the filter/Accumalator is a low pressure switch. It is used to shut the compressor down when the low side pressure reaches about 10-20psig. this keeps the low side of the compressor from going into a vacuum and pulling air and contaiminates into the system.

    The high pressure cut out switch is usually mounted on the compressor if it has one. Most vehicles don't..

    It depends on the maker of the vehicle on how they control the temperture of the vehicle.

    You will need to use a relays for the a/c clutch and the blower motor.

    It is possible to do what you are trying to do.
    Last edited: Sep 8, 2012
Ask a Question
Want to reply to this thread or ask your own question?
You'll need to choose a username for the site, which only take a couple of moments (here). After that, you can post your question and our members will help you out.
Electronics Point Logo
Continue to site
Quote of the day