fbpx

 

Ok today I replaced the rubber fuel lines on my 2004 582 blue head, including the fuel pump diaphragm. Didn't touch the electrics but on the test run I notice that the water temp gauge isn't reading. Hmmm check the connector, it's all firm must be the sensor broken. Shut the engine down and as soon as I turn the ignition switches off, the temp gauge comes to life!!!

Anyone out there experienced anything like this? It's clearly not the sensor, why does it work when I shut the engine down and stop when the engine is running. The aircraft hasn't had any major mods, it's an airborne ws outback.
  • Re: 582 blue head temp gauge problem!!!

    by » 8 years ago


    Jeff.

    Sounds like something strange with the ground line. I'm assuming you have the mushroom top sensor that a single wire with a spade connector connects to. The engine block serves as a ground wire. You obviously have a good connection from the top of the sensor to the gauge or the gauge wouldn't work at all. Ground wires have a tendency to corrode even though tight. I would check all the grounds. from engine block to frame, frame to gauge, etc. You might even run a temporary ground straight from the ground connection on the gauge to the probe or engine block.

    One sure fire way to check the gauge and the probe is to remove the probe from the block. Hook a tempoary ground to the probe and dip it in a pot of boiling water. If the gauge reads 212f, the gauge and probe are OK and the problem is definitely in the ground wire.

    If you have spade connectors in the ground or probe wire anywhere, unplug and replug the spades. The amount of amperage through those wires is so tiny that the least amount of corrosion can open the circuit.

    The fuel pump lines are all very close to the block ground and the wire bundle coming out of the alternator. You could have just moved a wire enough to affect the gauge.

    I would just about bet that the problem is somewhere in the ground circuit.

    Bill.

    Thank you said by: Jeffrey Thompson

  • Re: 582 blue head temp gauge problem!!!

    by » 8 years ago


    Thanks so much Bill, I will go looking!

  • Re: 582 blue head temp gauge problem!!!

    by » 7 years ago


    Ok so the problem continues. Today checked all the wiring, 12 and a bit volts on the power to the temp gauge when the key is switched on, good earth circuit from sensor to gauge and good resistance on probe to earth. So no wiring issues, but a discovery - the gauge works correctly when the engine is STOPPED and sits on zero or thereabouts when the engine is running. Nothing to do with the ignition switches which had me puzzled for a while.
    So if wiring is good, must be the sensor, and somehow running the engine causes it to cease working. I'm going to buy a new one a see if that works. Any ideas apart from that.

  • Re: 582 blue head temp gauge problem!!!

    by » 7 years ago


    Jeff,

    It still sounds like a wiring problem. The probes are cheap and easy to replace and its worth a try but I doubt it will cure the problem.

    When the ignition kill switches are in the STOP position, a ground circuit is completed between the modules and ground. If the temp ground is somehow wired through that ignition ground, the gauge would work when the kill switches were put in the STOP position and would not work in the RUN position.

    I'm assuming you have a key type start switch which has a START and ON position? If so, start the engine and let it warm up a little. Leaving the starter switch in the ON position, switch the kill switches to the STOP position. at this point the the engine stops and the gauge begins to work. without restarting the engine, switch the kill switches back to the RUN position and see if the gauge stops working. If the gauge goes from working to not working as you switch the kill switches on and off, then the gauge ground or probe ground is somehow working through the kill switch ground.

    Try that and see what happens. This test won't cure the problem but it will help tell us where the problem is.

    Bill.

  • Re: 582 blue head temp gauge problem!!!

    by » 7 years ago


    Will try this arvo and let you know. Thanks so much Bill

You do not have permissions to reply to this topic.