Brake Light wiring problem

[Bill T.]

I have a 78 Super that Was given to me but it has been no gift. It has lots of issues. One of which is that pack rats ate a significant amount of the wiring. I’m trying to sort out the lights. I have running lights but no brake lights. I can’t seem to locate 1. The power source for the lights and 2. The actual wires that run from the fuse panel to the rear of the vehicle

I’ve studied the wiring diagram and it looks like fuse #11 is the brake light fuse. And it looks like it should be hot all the time. What color wire supplies the power?

Will the brake lights work if the horn is disconnected?

Thanks for the help
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'78 Super Beetle Convertible
'72 Triumph TR6

[mukluk]

Your brake lights (M9 and M10) are on tracks 38 and 41 in the diagram below. Power comes through fuse 11 when the ignition switch is on, running from the fuse via a black wire to a single connector (T3a) where it splits off to the horn via a black and yellow wire, but also continues through the connector to the two brake light switches (F) via a pair of red and yellow wires. The blue and brown wires shown at the switches go up to the brake warning light (K7) on the dash. From the brake light switches should be a pair of red and black wires that join together at another connector, a single red and black wire then running from there back to the rear of the car where it again splits into two wires that run one to each brake light.

The brake lights should still work if the horn is disconnected, provided it is the wiring located at the horn that is disconnected and not the black power wire at the output side of fuse 11.
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1960 Ragtop w/Semaphores "Inga"

[Bill T.]

Hey man, thanks for the handy diagram. Having colors helps a lot. I’ve managed to repair the wiring from the fuse, to the brake light switches, and to the tail lights. I’ve hit wired them and they work! Had to replace the master cylinder in the process.

But, I have no black 12v switched input anywhere. I’m not sure if the pack rates got that, or it was pulled out for other reasons. So, I’ve got to find another 12v switched option. I’d rather not piggy back on another circuit, but I really don’t want to crack open the steering column to solder in a new wire.

Any advice? What if I swap out all of the running light bulbs w LED? That would significantly cut the load on each circuit. Then I could use fuse 1 and 2 respectively to power the brake lights (LED also).

Kinda hackey, but my enthusiasm is waning
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'78 Super Beetle Convertible
'72 Triumph TR6

[ashman40]

[Bill T.]

Mukluk/ashman you are great!

Mukluk, the colored wiring diagram has been very helpful. I’ve been using it. Along with the book to figure out what is supposed to be where. Like I said the pack rats did a nasty job on the wiring. Who knew wire insulation was so tasty! A great deal of the wiring in the rear drivers seat well is just gone. Stubs of wires laying there like tree stumps after a hurricane

Ashman, thank you for the info on the location of the origin of the 12v “running “ wire. I was able to trace that black wire from the plug at the steering wheel and learn that it had been run directly to the electric fuel pump. It then came back to terminal #11 to supply power. Creative wiring at its finest.

I’ve still not been able to get much of anything to work, but at least I found the mysterious wires and tested the black primary wire from the switch to ascertain that it indeed shows 12 v at start and run. The black/yellow wire shows 12v at run.

I will probably be bleating for help again in the future
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'78 Super Beetle Convertible
'72 Triumph TR6