I'm confused about wiring for my 1991 E350 Collins short bus - specifically with turn and brake lights. I'm hoping for some clarity from those with a similar setup.
Specifically, the bus has had all the old bus lights removed, except for the rear 7" amber turn signal lights. Running lights work in rear, backup lights work, and turn signal works. But there are no brake lights.
Looking at the standard (non bus) E350 schematic from my Chilton's manual (picture below), it looks like both the turn signal ("marker light") and brake light ("rear stop light") share the same wire from the front. Meaning the same bulb is used for both. Specifically, the same filament on the 1157 dual filament bulb.
That leads me to believe that on the bus, since you don't want your amber turn lights coming on when you brake, there must be a second, dedicated, and bus-specific wire just for the brake lights going to the standard tail light assembly. So one light for turn signals, another for brake lights.
Does this make sense as a modification that would have been done by Collins when they built the bus? And specifically that I am missing this wire?
E350 rear light wiring
by Tim Holt
, on Flickr