At last!!!!

Just got to bottom of my electrical faults!!! A bad earth was causing havoc with my instruments, Light would dim when i used the indicators, the radio would go off randomly and the blower speed was up and down like a yo-yo. Any way it seems that the earth lead behind the battery has a clamp around it,(the small clamp was supposed to fit around a stripped part of the cable and bolt to the body along with some smaller wires. This was very loose, so i have tightened everything up and it seems to have done the job!!!!
I'm still gonna check the other earth as was suggested on here, but looking at the wiring diagrams in the manual, this one is common to all the circuits (being the main earth).

i ahd the same problem and it was down to that earth strap being disconnected