TheSamba.com :: View topic - 65 deluxe brake light mystery- solved

Thu Jun 26, 2025 7:54 am

65 deluxe.

Trying to understand why one brake light does not work.

All lights worked when i parked it a few years back. Wiring is in good shape. German parts other than my two relays. rear light housings have independent grounds to the chassis strap in engine bay.

I thought i had it traced to the turn switch now not sure. Main clue is my emergency flashers work to all lights but my rear left brake light does not work. This means my relays, bulbs, sockets and wiring to rear are OK.

Below is my test chart for what works and what does not.

I know my brake switch is bad so i am shorting that to test.

My focus was the turn switch as that is where the emergency flasher system and brake lights merge. (54St to HL or HL to "Y") (Image below is my turn switch)

Everything has continuity.

- Brake switch to 54St on turn switch. Good.
- 54St to HL on turn switch. Good. ( Also tested HR )
- HL on switch to Emergency "Y" in harness. Good
- Both wires leaving "Y". To light & relay. Good

What am i missing?

Here is the 65 wiring schematic.

Fri Jun 27, 2025 6:56 pm

E-Flasher switch bypasses the turn signal switch. So would suspect the turn signal switch or a bad wire from TS going to the LR electrical junction the E-Flasher connects up to.

Fri Jun 27, 2025 9:21 pm

Huh - that never occurred to me before, but E&B point out that the eflasher switch is basically backfeeding turn signals through Y connections downstream of t/s switch. So the HL 'y' or the inner switch connection from power to HL is suspect.

Sun Jun 29, 2025 10:44 am

Thank you.

Solved. Turn switch.

Measured voltage to find it.
54bl, Hr, Vr and Vl all had 0-12v measurements. This indicates that from 54bl to Hl I had an open.

Sprayed some co tact cleaner/lubricator on the switch. Amazing the crap that came out but that fixed it.

Coupled with a new ATE brake light switch and I am 100% electrically good.

Sun Jun 29, 2025 11:54 am

Thanks for the update!! Yes, a good electrical contact cleaner is a good thing on the old turn signal switches. We are still using one with silicone that we bought from Radio Shack many moons ago.......