I have just bought a vendo 126B on e-bay ($150). The big main sign lights up. There are two other lights that do not light up. The question I have is do all the lights run on one ballast, or do I need to replace the ballast on the light in the vending door and coin change slot?

the Vendo V126 should have a two separate ballast for each light, ( one for the lightup coca-cola sign & one for the bottle-door light) the correct-change light is a C-7 bulb night-light style bulb That snaps into the side of the coin-bezel & only should come on when the machine has no nickels left to give change) or you can use a S-7 indicator bulb too. it has no ballast.