Announcement

Collapse
No announcement yet.

Help with Troubleshooting Air Conditioning

Collapse
X
 
  • Filter
  • Time
  • Show
Clear All
new posts

  • Help with Troubleshooting Air Conditioning

    New to forum after recently purchasing a 07 Prado 120 VX. I have visited Pradopoint in the past, but unfortunately making my first post today due to a problem with A/C.

    With no advance warning sign and after consistently blowing nice and cold, this morning the vehicle started up but without any air. The previous night I was trying to solve a problem with the car alarm (installed by previous owner). While searching for the alarm control unit under the driver and passenger side dash I bumped against and tugged on a number of wire bundles.

    I don’t have much experience with A/C, but because it failed so suddenly and unexpectedly plus my previous contact with the wiring, I am thinking it could be an electrical/control problem.

    Here’s what I have checked so far:
    • removed the lower dash panels on both sides and the interior fuse panel to gain access
    • disconnected and reseated all the electrical plug connections in the areas I was working in the night before
    • adjusted all the wire bundles and wire harnesses to relieve any strain on wires/connectors
    • removed and reseated all the fuses related to air conditioner, heaters, and blowers in both the passenger compartment and engine compartment fuse boxes
    • removed and reseated the relay for the a/c compressor clutch in the engine compartment fuse box.
    That is as far as I got today.

    I could be mistaken, but it seems to me that the compressor is not engaging.

    Any advice on what to check next (and how) would be greatly appreciated.

    I have automatic climate control.

    Thanks in advance.


    Cheers,
    Wess
    07 Prado 120 VX 1KZ-TE

  • #2
    I am thinking of checking next to see if the AC compressor is receiving the signal to engage the clutch, since everything else seems to be working fine - just no cold air.

    There is a wire with a connector attached to the compressor that I should be able to disconnect and put a voltmeter on it. I would think that 0 VDC would be OFF and +12 VDC would be ON. If anyone has checked this before and can confirm it would be very much appreciated.

    If there is no signal then I could check the relay next to see if it's working properly. When I pulled it out to reseat it, I put a multimeter on it and found open circuit resistance across the copper pins and a moderate resistance across the metal pins, so it looks like the copper pins are the relay contacts and the metal pins are the coil.

    To test the relay, can I take power straight off the battery or do I need to use the regulated power of 12 VDC?

    The other thing I am thinking is to test to see if I can get the AC clutch to engage. Can I put a jumper on the the relay contacts in the fuse box? Is that safe to do?

    Does anyone have a Wiring Diagram they can share? Or recommend a good source for one. I have used Haynes Manuals in the past for previous vehicles but I don't have a manual yet for this Prado. Not even an Owner's Manual.

    Any feedback would be appreciated.


    Cheers,
    Wess
    07 Prado 120 VX 1KZ-TE

    Comment


    • #3
      Is the A/C light blinking? If so, it's the magnetic clutch relay.

      Comment


      • #4
        Hi amts, thanks for your reply. I don't have a blinking A/C light. This arvo I started at the compressor with a voltmeter and when switching the air conditioning ON and OFF at the dashboard control panel, I measured 0 VDC in both states. So no signal to the clutch, as suspected.

        Then I worked back to the magnetic clutch relay you mentioned. To check I had the right relay, I pulled it and did a continuity test on the terminals the relay plugs into and confirmed one of the terminals associated with relay contacts is connected to the compressor clutch.

        I was able to test the relay by applying power to the coil side and I could clearly hear the really clicking when power was applied and removed. I didn't have enough hands to test the continuity of the relay contacts while energizing the coil, but I reckon that the relay must be functioning properly because if it was bad it would be due to a burnt out coil.

        I was tempted to jumper out the relay to see if I could engage the compressor but i decided not to. It would probably be fine to do that, but I just wasn't sure if there might be some other components in the system or interlocking relays, etc. and didn't want to make matters worse.

        So I stopped there. What I really need now is a wiring drawing.
        07 Prado 120 VX 1KZ-TE

        Comment


        • #5
          Two other checks you could do is 1) Check that the relay is operating when the A/C is turned on and off. 2) Check that power is getting to the +ve relay contact. Many fuse connectors can corrode and/or go open circuit with age. Connectors are that most common points of failure in electrical systems.

          Comment


          • #6
            Hi GeeWhizz, thanks for posting. Yes, I did check both those things a couple of days ago. I mentioned doing the two checks in my last post but I referred to the same relay you mentions as the 'magnetic clutch relay', since that was how it was named in the diagram on the cover to the engine compartment fuse box. Diagram calls it MG CLT.

            So yes, an excellent suggestion, but unfortunately the control signal is not reaching the coil of the relay. Before tackling the relay, I pulled and reseated all the fuses that looked to be related to the ac system as well. I was pretty careful but maybe I missed one that might be part of the circuit but not with a name that would suggest it. Perhaps I should go back and pull/reseat every fuse in both fuse boxes.
            07 Prado 120 VX 1KZ-TE

            Comment

            canli bahis siteleri bahis siteleri ecebet.net
            mencisport.com
            antalya escort
            tsyd.org deneme bonusu veren siteler
            deneme bonusu veren siteler
            gaziantep escort
            gaziantep escort
            asyabahis maltcasino olabahis olabahis
            erotik film izle Rus escort gaziantep rus escort
            atasehir escort tuzla escort
            sikis sex hatti
            en iyi casino siteleri
            deneme bonusu veren siteler
            casibom
            deneme bonusu veren siteler
            deneme bonusu veren siteler
            betticket istanbulbahis
            Working...
            X