Here is a shot of the lower dash elements on our 2008 Chevy 2500 RT170P:
Left to Right Descriptions.
Stock Chevy Express Ciigarette Lighter.
The ML-ACR switch is no longer connected to the Blue Seas Charge "Solitter" - it has been removed. Now have a B2B instead. Keeping the switch in place for future options.
Stock Airbag labels.
The instruments:
Start Battery - monitors Alternator Output. Topline is VOLTAGE to the Start Battery; Lower Line is AMPS.
The next instrument monitors temperatures. The TopLine is Alternator Temperature; Lower Engine Bay Temperature.
Both of these are activated by the Lighted 2-way rocker switch.
CAUTION - it is wired directly to the Start Battery!
The next rocker switch is currently unallocated.
The first 12v Cigarette port is measuring house voltage via a link to the B2B.
USB Port is connected to Starting Battery.
Cheers - Jim