1980 Freightliner wiring

I've got a few things I'd like to wire correctly, everthing from previous owner is kinda a mess.

1. Low air warning. Is the light and buzzer on the same switch? Is it susposed to be N/O or N/C (it's not working).

2. Headlights, have been wired to a 3-way switch on the dash.

3. How are the electrical systems protected? Fuses, circuit breakers, can't find a junction box for all systems.

4. what bulb is susposed to be in the warning lights? Most are missing, and can't find a number on the broken ones.

 

Let's just say it looked good in pictures, and the owner said it was a good truck. Bought it on a online auction, as a grain truck. Didn't know so much could be wrong, but still working condition.

 

It's a conventional FLC-12064-T 183177

I've got a bunch of parts ordered. Light bulbs included. I've got two pressure switches on the valve block behind the steering shaft. I don't know what the one the top tow to the right is for, can't follow the wires. The one on the bottom row, is currently connected to the light, and buzzer, and is not working, ordered a new one.

I'm gonna have to figure out what panel to take off to see the circuit breakers. Had the A/C Heater control panel off, but didn't see anything easily acessible.

 

I took a few pics. Found the circuit breaker/ relays?