No you want the relay in the "run."
so whatever color IGN1 (usually dark blue) where it comes out of the bulkhead, that is 12V in "run" position of key
Electrically cut that, use the bulkhead end coming from interior to trigger a relay. Feed the relay through a fuse/ breaker off the start relay big stud (battery) and take the engine harness end of the cut blue and connect that to the load contact of the relay
"How it works." When there is voltage drop in that circuit, the feed going to the VR power (IGN terminal) is also the SENSE wire. It senses voltage is low, and ramps up the alternator until that point (the VR ign terminal) is 14V. "Whatever" the voltage drop is through that circuit to the battery, resistance in that path causes drop there at the VR. So now it is 14, but the battery, which is isolated by the drop, is now seeing 14 + whatever the drop reading is
