door lock fuse keeps blowing

[ON_DUBS]

I have a series 1 Fairlane, the 30amp fuse for the central locking keeps blowing if I try to lock the doors.
The boot release operates on the same fuse, it does not cause the fuse to blow.

I have tried the following:

Unplugged all the actuators,
I was able to determine that the fuse only blows when either of the FRONT door actuators are plugged in.

I inspected all the wiring in the doors, no damage.

Removed the trailer plug.

Unplugged the door lock button from the dash.

Had a friend (electrician by trade) check it out, the actuators tested ok.
Checked all the actuator plugs and the circuit diagram for the door lock system.
Was able to trace the problem back to the BEM or wiring in between the BEM and actuators.

I replaced the BEM, i pressed the door lock button once and it worked without blowing the fuse.
Ok so that seemed successful but the new BEM wouldn't work with smartlock.
I started trying a few things to get it to work, I pressed the door lock button and the fuse blew again!

So either the BEM was not the cause of the problem OR
I have another screwed BEM now becuase of another fault somewhere.

I have heard this issue is a common fault with the AU or at least series 1.
Couldn't find much doing a search except for one other case where somebody had ALOT of difficulty fixing it.

Can any help?
Thanks