Outer Limits 4x4 Board

I recently installed a mongoose mx40 on my swb gq... it has two relays for immobilising two circuits. The first i have put on the starter..... the second I am looking at putting on the first side of the ballast resistor.... therefore cutting the coil...., to my knowledge this circuit doesn't draw high amperage and would be safe to pass the internal relays of the immobiliser.... am I correct in thinking this..??? what is the normal way of immobilisng the ignition circuit if not....

Thanks