Hi George,

I've now done the job and it worked - the MOSFET hadn't failed yet - the addition of the diode was all that was needed to restore that magic carpet ride. Thanks to everyone - especially you, Noz and techmanagain - I wouldn't have had a clue about all this without the help available here.

This surely is a "must do" job for everyone - whether your suspension is working correctly or not (or even if you think it's working correctly).

I was a bit wary of even trying to solder directly onto the wires leading to the ecu connector as techmanagain had the confidence to do. Instead I used 15 amp snap-on / cable-lock / piggy-back connectors to link my own wires from the ecu connector cables to the diodes which I'd soldered onto a piece of circuit board mounted in a little plastic box that I stuck inside the black weatherproof box that holds the ecu's.

If anyone else is thinking about this - maybe the following information will be useful.
On my car 2.5TD (RP 6958) the cables were identified as follows:

All cables were on the white ecu connector plug (there's also a black plug on the ecu).

The lead for the front electrovalve is yellow and has the number 3 printed on the insulation. The lead for the rear electrovalve is also yellow and has the number 18 printed on the insulation. There are 2 blue earth wires (same gauge as the yellow ones) - you can use either (see below) - there are no numbers printed on these. The marked end of the diode must be connected to the yellow lead as mentioned in earlier posts.

Noz / techmanagain,

I looked up the wiring diagram from Noz's CD (580-2/20b on pages 1449/50) and it seems to me that it's OK to use a common earth - as techmanagain had originally done - as these appear to be common anyway. If I'm wrong can someone please let me know.

Many thanks again to everyone

Roy

This post has been edited by mackay1 on July 21, 2006 08:01 pm