After running some performance tests (pretty mild ones!) tonight, I stopped to fill up with petrol. Pulling away, I noticed the spoiler light stayed on. Then I realised that this was because the speedo is dead.
It doesn't seem to be a fuse - anyone got any ideas?
The whole unit is dead - no mileage counting, no needle movement, spoiler doesn't rise on cue.

 

OK, guys -

found a lot in the archives.

 

John,this maybe an easy fix like it has been
for me. I have a C4Cab that has had this
same problem. There is wire harness on the
right side of the transmission that plugs
into a female receptical on the right side of
the transmission. Note:You will have to remove
the under tray if yours is still attached in
order to get to the wire\receptical. The wire
may have broken off the male plugs or the plugs
may have only come out of the receptical. The
second time that I made this repair,I re-soldered
the wires to the male plugs. <img src="graemlins/beerchug.gif" border="0" alt="[cheers]" />

 

John

I had exact simptoms when removing my speedo, did not put the plug back on it tightly enought.

Regards
Rob

 

Well, either

A. I have fixed it by breaking/making the connection on the back of the speedo head.

or

B. It's one of those annoying intermittent faults, which always SEEM to be fixed, but...