Cheers David & Adrian,
David... that was my next thought, as its worked ok in the past 
 
 
Adrian....
The gause has...
terminals for 
Positive +
Negative -
from sender
 then has a wire from the gauge for the gauge light that goes into a little black box ( each of the gauges has this box ), then from the little black box its then connected to the cars lighting wiring.
Everything works apart from the Oil temp gauge, it shoots off the scale.
I got the gauges off ebay, might have to contact them & ask what maybe wrong etc, maybe they,ll replace the possible faulty gauge or sender 
 http://cgi.ebay.co.uk/Meter-Gauge-OI...item2562496cdb
 http://cgi.ebay.co.uk/Meter-Gauge-OI...item2562496cdb
This is the gauge , 
cheers
andy