So the Rotten Passat is getting the dash removed for good in my 500 pound weight reduction goal. I was going to use an OBD device with my phone in order to watch temperature, rpms, speed, etc so the instrument cluster will be deleted too.
My issue is that the alternator signal wire runs through the instrument cluster then on to the alternator. Is it as simple as putting a on/off switch in line in place of the instrument cluster then watching the battery voltage in order to turn the alternator on when it gets somewhat low? Ideally I would create some sort of electrical thing that would turn it on when it got to a preset voltage and off once charged but that would be down the road.
Here is the wiring diagram (To see larger right click then open in new tab):
