Ok finally got round to it,just put on a new battery and double checked operation of air compressor by taking it off and putting power to it and it seems to work fine.Put back together and there is no light at all on the dash where the height level lights are.I think it always had the red light at mid position before I fixed the compressor so why do I have no light at all.Have checked the fuses I think are the right ones one in the rear[50a] and one in the front that seem ok.My friend brought his laptop but for some reason he was not able to read it .Any ideas,i have another mate who is going to have a look this week but any info will be appreciated,thanks.

Engine on, steering wheel fully left then fully right, switch off, switch on engine again and see what happens.