79 camaro factory idiot gauges
 

just bought a new project for my daughter,orig a 6 cylinder car,has a nice 350 and turbo 350 in it now,trying to get the idiot lights to work,having problem with the tan wire for oil switch,keeps burning the switch up,found out it has:icon_shrug: 12 volts on it and killin them,yea I could put some new gauges in it,but like to get these to work right know..any suggestings...

According to the wiring schematic, the 6 cyl model (yours) oil pressure switch had 2 wires, an orange and a dark blue, not a tan. 8 cyl cars had only a dark blue wire. There are tan wires that connect to the headlights, and the idle stop solenoid at the carb, and the brake low pressure switch on the junction block. The oil pressure switch creates a variable ground path, so I get why it burns out with power going to it, just surprised you're not popping a fuse too. Is your under hood wiring a jumbled mass of spaghetti? You have some crossed/misplaced wires.

The pressure switch is just this - a switch - on/off at about 7 PSIG.
A gauge uses a variable resistor - more pressure, lower resistance = lower gauge reading.

Idle solenoid 'tan' wire could be switched.