self leveling not working.

Well ive had a few months with no disco problems.
However, I noticed a knocking when driving through my field which i assume is associated with the fact that my rear suspension will not raise any more. Ive checked the things posted here and google and am now at a loss. to eliminate: The air filter behind the left rear light is clear, The fuse is not blown, the air bags seem in ok condition, one of the level sensors rubber connector is split but this was easily fixed. I have taken the cover off the compressor housing and all seems in good condition other than its not working. I get the 3 dings if i try to raise the rear with a door open but nothing happens when they are all shut. I have just had a look at the connectors in the passanger footwell but nothing jumps out. I did have corrosion with courtesy light and rear wiper but all the other connectors dont show any corrosion. I have tried looking on rave to see if i can track down if/where the wires connect to the slabs but failed to find anything useful. The disco is due for its MOT in a couple of months but i want this fixed ASAP as im worried about it sitting too low when im in my field.
I welcome any thoughts and advice.
Rob.

Have you checked the under bonnet fuse and relay?

oooh. not the relay. ill go look now. is it clear which it is?

just swapped relays around and still not working. could feel the relay clicking though. I was all excited there

You need to have all the doors and bonnet shut before the bags inflate.

sorry to contradict but the bonnet has nothing to do with it only the doors/taildoor... if there was a sensor fault and it was disconnected or other plugs disturbed there's a fault code logged in the ECU which disables the system untill it's cleared... also even if the doors are all closed dont you eventually get a misslock warning when you lock the car?

if you hear the relay clicking and no compressor sound it means the comporessor is gone... to make sure remove relay R5 take a piece of wire and bridge the holes in the fusebox corresponding to terminals 30-87 of the relay(they are pointed on the relay...concentrate to not mix them)...if still no action from the compressor then that's it ...you need a known good one

Never knew that, every day is a school day, here's me when working on the SLS always shut the bonnet:doh:

thanks. will look 2morrow.