At this point, its hard to say. The starter draws a lot of current. More if its not getting full voltage.
With the problems you were having, its possible that the solenoid was damaged and is sticking.
The solenoid is fired by the purple wire. If something is keeping this hot, then the starter will crank.
Before you try anything else, check to be sure that the purple wire is not close to the lug going from the solenoid to the starter.
If not, then you are gong to have to troubleshoot the system to tell what is happening.
I know you don't want anymore wiring problems, but you might try cutting the purple wire, hooking on some extensions, and either splicing it where you can get to it, or adding a switch.
Then, if you can get it to keep cranking, break the connection and see if it stops. If it does, then its in that circuit, possibly the ignition switch.
If it keeps cranking, then its the solenoid.
With the problems you were having, its possible that the solenoid was damaged and is sticking.
The solenoid is fired by the purple wire. If something is keeping this hot, then the starter will crank.
Before you try anything else, check to be sure that the purple wire is not close to the lug going from the solenoid to the starter.
If not, then you are gong to have to troubleshoot the system to tell what is happening.
I know you don't want anymore wiring problems, but you might try cutting the purple wire, hooking on some extensions, and either splicing it where you can get to it, or adding a switch.
Then, if you can get it to keep cranking, break the connection and see if it stops. If it does, then its in that circuit, possibly the ignition switch.
If it keeps cranking, then its the solenoid.