New here, thanks for your patience and advice. Working on a 1985 6.9L e350 diesel and here's my issues:

Glow plug controller or glow plug went out-tried starting it up and the glow plug indicator light fails to come up, so I bypass the controller to the relay which solves the problem when installing an on/off switch. Complicated emergency fix because it was parked on the street in SF and we didnt wan't to get towed.

other issue is the brakes, was driving down the highway and lost pressure to the brakes, brake light indicator came on, burning rubber smell was present. Not sure where the master cylinder is at, does this mean there is air in the lines and ill have to bleed the system?

any advice or procedural advice would be so helpful-thanks!

 

From the question you asked regarding the master cyl, i hope i'm wrong, but you would be better served to have the brake work done by someone who is more experienced with brake systems.