I always wire directly to the battery; it's the very best place to monitor "battery voltage". Wiring it anywhere else doesn't take into account the effect of wiring harness loses, especially if heavy draw accessories are running on the same line. But the easies and neatest place is right at the starter solenoid where the heavy red cable from the battery is connected.>If you wire it straight to unswitched battery voltage
Any suggestions on exactly where to wire it to?
Good idea !!