Electrical Gremlins......Conundrum

I have the battery in the trunk - wired to a shutoff switch,


From the Battery, I have 1/0 gauge wire to a bulkhead connector in the firewall, from there, 2 gauge wire to starter.
Also from the post I have the blue wire from the bulkhead connector (With the fuseable link)
Sorry my friend from your description I'm confused You ran the battery cable "where?" Maybe to the stud on the starter relay? I'd have run it direct to the big starter stud and a SMALLER wire up to the starter relay, then taken your feeds off there

Also from the post I have the blue wire from the bulkhead connector (With the fuseable link)......

Don't know what blue, the fuse link is normally connected to the red ammeter wire Can you explain



I have the relay under the dash - hot wire to the post, and the correct wire from the factory bulkhead connector (Yellow) to the angled post on the relay.
As soon as I turn the power on, the starter is cranking......

First thing I'd do is separate the yellow wire from the start relay and then at least you can start to troubleshoot

So far as cranking, don't discount a short---maybe either of the cables at the starter is bridging across to the other one, same deal at the start relay

If that gets you nowhere, with the yellow "start" wire disconnected from the relay does it still crank? If not test the yell it should be "dead." Wiggle key see if it comes alive intermittent

If engine cranks with yellow pulled loose, pull the big wire off the starter relay "square screw" which goes to the start relay and try again. If it still cranks it's down at the starter, either one of the wires on the solenoid is bridging, or there is something wrong with the starter or solenoid