My EAS system has become somewhat ambivalent about turning the compressor off when everything is up to pressure. Takes a short 5 minutes to come up to pressure from all empty so at least I got the compressor rebuild right. Once its up to pressure you get the usual solenoid clicks, small puff from the exhaust, short pause then the compressor runs up again for, usually, a short minute before repeating the cycle. Pause after exhaust puff and compressor run time vary rather pause is always less than a minute, run time sometimes goes over a minute. Sometimes it decides to work normally after an indeterminate number of short run cycles, sometimes it carries on for the whole journey. Occasionally you get a very long discharge from the exhaust suggesting that sometimes it goes well over pressure. Fortunately I've not been out and about much over the winter so its not been a major worry but really need to get it sorted now the wether has turned. I have two valve blocks both of which exhibit the same behaviour. One from LandyAir and my old one which I rebuilt.

Had another go at it today and with the ex-LandyAir valve block it was short-cycling about 3 to 5 times after height adjustment before settling down. The Lynx diagnostics says pressure switch normal during pump up and short cycling and pressure switch low once the compressor is properly stopped. Which is right. The other valve block just keeps short cycling for as long as I was prepared to run things, 10 minutes or so.

Pressure switch is the obvious cause of the problem. But two bad ones seems a bit unlikely. Especially as my valve block worked fine before I fixed it!

Clive

I would vote for an iffy Driver Pack !

If the pressure switch is actually switching, then yes, it sounds like the driver pack. Bear in mind that it might be cutting in and out because it's losing pressure from the tank, either past the threads of the pressure switch or through the undoubtedly leaky NRV.

Or bad contacts in the plug between the driver pack and valve block.I took a known good, fully working, valve block and compressor off one car and put it on another. It did nothing. Sprayed the multiway plug with contact cleaner, reconnected and it all worked perfectly.

Ha. The power of the Forum. Post up a question and things start behaving.

Did the contact cleaner thing when all this started. Nearly automatic reaction to reach for the contact cleaner can when electrics troubles are possible.

Up at normal height this morning confirming no serious air leaks, if any. As expected with the ex-LandyAir valve block. Pressure switch resistance this morning was nominal zero so switch appears to be working and tank up to pressure. Usual self levelling dance on start up. Compressor ran for maybe a minute followed by the usual solenoid chunterings and exhaust air puff. Tank probably stayed full overnight. After another minute or so the compressor restarted and ran for about two minutes followed by the usual solenoid chunter and exhaust puff before shutting down. No compressor restart within 5 minutes so it was probably properly shut down.

Put it down to access height and bought it back up to loose some air. Compressor ran for about 2 minutes before stopping. A bit long I felt but not unreasonable. After a short pause following usual the solenoid chuntering and exhaust puff the compressor started up again and ran for a further two minutes before shutting down properly.

Still leaning towards an iffy or sticky pressure switch but same fault on two valve blocks does suggest a car related issue. Same why both problem if its a bad driver pack. I suppose it could be switch on one and driver pack on the other.

Anyway seems to be working acceptably for now. I hate these "didn't understand the problem, not sure if its really fixed" things.

Thanks

Clive