I have an Atlas HO S4 diesel switcher with non directional headlights, ( so Atlas says ). I only run in DC mode. The headlight on the cab side doesn't work, the front one always works in forward or reverse. I bought it as new old stock and it looks new, a good runner. I'm assuming either the wire attached to the rear headlight is disconnected or the bulb is a dud. I've never done this before, so would I have to take the cab off, would that give me access to the wiring and bulb? Does the cab come off seperately from the rest of the shell? I'm fairly descent at soldering if that needs to be done. Any help would be appreciated, thanks, Bo.