Trying to get some ideas before I go tearing into this. Here is the background -

Leave for Hawaii for three weeks (not vacation, work)
Come back truck is dead. Notice I left my cell phone charger plugged in. Take out batteries, take to Kragens to get recharged. Re-install fully charged batteries. Fire truck up, throws a code. Its low voltage related. Figure its due to the low batteries. Trucks runs fine, but now both my Transmission and Pyro gauges aren't working. Boost is fine. Both display the back light when lights are turned on. Any thoughts? Thanks for the help!

 

How is the hot wires connected?? Are there any fuses blown?? Just my input.. 'cuz the light wires should be separate from the hot wires for the gauges.