Tail lights, brake lights, turn signals on '75 22'

[mendosoft]

I've had some work done on our trailer and during the work we noticed that the 4 rear lights were wired as follow, from left to right:

Left outside - tail light, brake light, turn signal
Left inside - NOTHING?!
Right outside - tail light, brake light, turn signla
Right inside - NOTHING

We've checked the wiring at the tow vehicle an all looks fine there. So we're wondering - how are these SUPPOSED to work? It doesn't make sense to hae the two inner lights do NOTHING? There must be a catch...

Thanks in advance for any insight.

Steve

[overlander64]

Greetings Steve!

The inboard lighting position was for the optional backup lights. If I am not mistaken, the wiring for backup lights is in the wall such that they could be installed as a dealer accessory. In coaches without backup lights, the position typically carried a red reflector.

Kevin

[Argonaut20]

On my Minuet I found the two inner lights were supposed to be back up lights. They didn't work and I doubt they would be useful if they did work. Find the connection in the 7 way connector that is supposed to be for back up lights, use a long wire to set up a continuity test from the trailer connector to the lights and you can tell what they are for (if the wiring in the trailer is OK). There is a diagram for the connector at Marksrv.com 7 way wiring diagram page. Apparently the center terminal is for the back up lights.

[Lumatic]

The most useful thing about back up lights is letting someone behind you know you are coming their way.