I'm adding a fuel pressure gauge.  Other gauges already in "A" pillar are trans, boost and egt. Since 2005.   All the light wires are from one place (not sure yet from where). But wire sure looks real small to me.

 

Basic Question on wiring...

To make sure I'm ok on this or any wire project...add up how much elec going to be going through and then select wire size based on how much going thru wire?

Wire gauge size should be based on AMPS and DISTANCE. Kind of like my solar panels in the yard are roughly 150 feet from the battery bank. It only 25 Amps at 24 Volts because of the distance I require 2 ought cable minimum to keep voltage loss down.