Wiring issues at clocks

hi got a 88 clipper cab    and am not havin much luck with the clocks in taking it its wiring as  tried another set of clocks  and same problems   i have no fuel or temp guages workin  no oil or battery light rev counter  idicators dont flash on clocks  clock  no longer works     can anyone tell me what each wire on the plug goes to   im presuming yellow was earth    got  12v from red wire and thin it was red n black one     but nothing  through the rest  does this sound like a earth problem  and does anyone  have any suggestions on how to fix

regards kev

there should be a black wire from the ignition switch which powers them up, but if the clock doesnt work either then its the earth thats gone. check brown/white wire this runs from the clocks to a single pin spade plug behind the fusebox, then this attaches to a plug on the engine loom then runs out and earths to the side of the head.

if you're struggling, just splice in another earth to the chassis to the brown/white wire