If you use or install the warning light, you have to remember that if the bulb burns out, the alternator will not turn on and the battery will discharge.
Terminal 2 "voltage sensing" can be connected at a different points such a fuse panel or distribution post. An example of need could be a remote battery location. The voltage may drop a little from long cable runs. The voltage sensing can increase the voltage a little to make up the difference. Normally it's not needed for our AD trucks.
"Adding CFM to a truck will only help at engine speeds you don't want to use." "I found there was nothing to gain beyond 400 CFM."
