AMK compressor fault

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AMK compressor fault

Post by sdm3873 » Thu Oct 11, 2018 9:14 pm


I have an 07 Disco 3 and it has developed an intermittent fault with the compressor not coming on. It is holding air in the struts ok but on occasion it vents and drops to the bump stops. When it runs again it lifts slowly and the corresponding message shows on the dash. So I know the compressor works and assume that it is raising slowly because the system is empty. On most threads that I have seen the common solution is just to replace the compressor. However I don't want to replace it before I am sure there is not something else causing it to shut down. My Icarsoft shows that the compressor is getting 14v although it is not running until the warning light comes on then the power is cut. I have taken the compressor out and it is relatively clean. The desiccant in the dryer is a whiteish and tan colour and some of the granules have broken down but there is not a lot of power which could clog the system. Not sure if this is an issue. I was checking the continuity in the cables and found that the red and white wires from the plug on the sensor cable to the compressor body have no continuity. Its been a long day but this tells me the wires are broken right? Does anyone know what the red and white wires are for and why they both go from the screw to the compressor body? Perhaps earth wires.

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Re: AMK compressor fault

Post by PillowSmuggler » Fri Oct 12, 2018 9:21 pm

I'm afraid I don't have an AMK compressor and have never seen one, however if I had to guess based on the gauge of the red and white wires I'd assume that these don't just go to the bolt, but to a thermistor hidden under the bolt - this would be used to detect the temperature of the pump casing. These devices tend to have a very high resistance when cold, and this drops lower as they get hotter but they wouldn't/shouldn't ever show as having "continuity" on a standard multimeter.

Regards, Dom.
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