Rear Lights Out

[september2018]

I have a question for my '73 B. Last night I took a spirited drive and on the way home lost all rear lights. My brake lights still work, but license plate and tail lights are dead. Head lights and fog lights work fine, same with turn signals front and rear. I have voltage at the fuse that controls the rear light circuit, but no voltage at tail light/license plate lights (red wires in boot). Bulbs are all good, connections are all clean and grounds are all good.

I’m trying to find the harness in the cabin where it runs into the boot. It runs over the RR wheel arch and then I lose it. My expertise is in Triumph so of course the first place I checked is in the foot wells as TRs wiring runs down the drivers side into the boot. Not the case with my MG.

Also with Triumphs there is a master plug that attaches front and back harnesses. Is there one in the B? I know I had tail light about 3 miles from home on the way back and didn’t realize they were out until I was informed about half a mile from home. All very nice roads with few bumps. Any ideas? Thanks in advance!

Tom Macken

[amgba]

Wiring to the rear of the car starts under the hood (bonnet) on the right side. Then down under the car. It has been my experience that where the wiring turns to go under the floorboard right side at the bottom of the firewall, this bunch of wires will rub the insulation off of the wires causing a mystery short.
Van Moore