Alright finished up the on board air
Tank is under the drivers side with a pressure cutoff switch that must be wired in the circuit of the power switch.
So I popped these off, drilled a hole, set a rubber grommet and popped off the factory grommet below it on the frame
This second photo is the underside of that hole. This is a great place to run wires into the cab, as there's great places to zip tie wires etc to along the frame around here-
avoid drilling into your body!
And the system cuts the relay off at 110 psi and it's all holding steady!
I can actually just Leave the compressor switch on all the time and it won't come on until I use it... But I won't. Either way makes it idiot proof and fail safe.
If you install on board air,
GET GOOD HOSE CLAMPS.
I had some piece of shit china made hose clamps that made the air system leak like a sieve when I first turned it on. All four connections were leaking so I trashed the dinky little ones & put bigger ones stamped made in USA and bam. It'll hold forever.
I used 3/8" hose and found some nifty places to run it inside the frame under the engine.
if anyone's interested ill crawl back under and take pics & share my secrets