is the low air warning indicator behind the dash?

I bought a 2001 379 pete and the wires need to be redone, but I need to work some first $$$. The low air incicator won't go off, I believe it is wiring, the pressure is staying at 120 when the truck is running, the pop out is at 30 when I do the safety check, by pumping the brakes. Every time I get something fixed and think I can pass a safety check, something else goes wrong, I am getting very discouraged, but gotta keep going, any help would be greatly appreciated.

 

Thank you, my problem is due to previous owner and a lot of chicken lights.

 

How hard is replacing the wiring harness?

 

I found the problem, it was the front brake drum, it was leaking bad, gonna have it replaced tomorrow, by my daughters friend, I'm not mechanical. Thanks for all the help, I love this forum, I get great advice here, faster than I can find it on the computer !