Premature starter

After changing to a new loom which required a change in alternator oil pressure and water temp plugs I have found when turning he key to the ON position the starter motor is engaging and trying to start the engine? HELP

Small wire to what?

If that is the round terminal ended one that us a white wire I have tried taking that off but found that I couldn't get the starter to work at all.

I have tried with the solenoid brown plug disconnected and then with the ring end wire and both ways prevented the starter from working at all. I am not sure what else to do. Might be time to call an auto electrician.

a bit of background info needed mate, this new loom you put in, are we assuming engine loom only, or body loom also?
 
is there anything modifed on the loom apart from changing the plugs you did, has anyone hacked some up and modified some wires, or better yet, did you swap because you old one was hacked out with some dodgy wires.
 
the only way the starter would crank when the key is turned to on is is somewhere along the line the STA line has been spliced to the IGN power. do you have an aftermarket alarm system? the guys who install these are butchers and hack the STA and IGN lines usually.
 
Start at the begining of the circuit, check out the wiring behind the ignition barrel, make sure the STA and IGN aren't exposed or touching. then follow through to the relay, make sure that checks out. If you have a multi meter you can check continuity between the STA line and the IGN line see if they are bridged anywhere, disconnect plugs to isolate sections to locate the bridge.

In case it helps anybody else, this was another lesson (I hope others have made the mistake) of check your earths, check your earths, check your earths. They can seriously mess with your electrical system. Thanks to all who helped.