Starting Problems any Help

Hi, All I have just not long bought a 1989 ex mod 110 already converted from V8 to 200 tdi I have been having a fair few problems since buying it last year but the worst is it won't turn over. Can anyone point me in the right direction. After going through some checks Im thinking its a wiring problem (Not 100% Certain though). I get all my dash lights when I turn the ignition on but when I turn the key over, Nothing!! Battery is good,Fuses are good, Removed the Starter today and bench tested it and the gear is kicking and turning which I guess is good.
Does anyone know if there is anything common with them or any suggestions

Fuses?

Check your earths!

There is a thin wire that plugs onto a spade terminal on the starter. It is the trigger wire from the ignition switch. easily missed when ya look for it. and always coming off the terminal or corroding.

Hi and thanks, I checked the fuses, I will recheck the little wire tomorrow for voltage but I'm sure it was on after i had tried to remove the starter before with no success after realising i had to take the down pipe off I made sure this was connected tried again before finally taking the starter off. Still worth another check

Heavy gauge earth bonding strap between the engine and the bodywork?