[T3] Emergency Flasher Wiring

[Jim Adney]

Thanks, Sean, for pointing out the complex relay w/simple switch vs. the 
simple relay w/complex switch. I never realized that this was what was going 
on.

It's worth pointing out that, at some point, and at least by '68, the relays 
incorporated a feature that caused the relay to flicker quickly if there was a 
burned out filament. This was enabled by sensing the inrush current that is 
normal with tungsten filaments. Switching to LEDs, which have no inrush 
current, disables this feature, but with LEDs that feature is much less useful.

Did the '66-7 TS relays also get this feature?

I still don't know what the '66-7 4-terminal TS relays look like. Does anyone 
have one that they can post a photo of?

Sean, you wrote about the differences in bulbs between bugs, busses, and 
Type 3s. Did you mean separate BULBS or separate FILAMENTS? Type 3s 
have one bulb with dual filaments at each corner, and I have always 
assumed that bugs and busses were the same. 

Jim

On 4 Mar 2026 at 18:07, Sean Bartnik wrote:

> There are basically 3 different versions of turn signal flasher relays and
> then some variations within each version.
> 
> Version 1 is on the early cars with no hazard flashers. Turn signals only.
> Simplest system, just a 2-terminal flasher relay: power in, flashing
> output, grounds by mount to the dash.  Easy.
> 
> Version 2 is the oeComplex Relay / Simple Switch system that started
> around TM66 when hazard flashers started to be legally required. I have
> wired up my TM65 with this system using period parts and following the
> TM66 wiring diagram and it works great. This uses the big 9-pin relay and
> came in 6 and 12v versions.
> 
> Version 3 is the oeSimple Relay / Complex Switch system which came
> later, not sure what year, where the relay is a small 4-prong relay and
> all the complexity was moved to the hazard flasher switch itself.
> 
> Anyway, the Complex Relay was used on all VW models of the time and so it
> has provisions that are not used on the Type 3. One of those is the 54 and
> 54f terminals. Those terminals are used on Buses and Beetles where the
> turn signal bulb at the rear is also the brake light bulb. Those terminals
> are used to interface with the power to the brake lights so that the turn
> signal (or hazard flasher) overrides the brake light. Those terminals are
> left unused on a Type 3 because we have separate brake and turn signal
> bulbs at the rear.


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Jim Adney, jadney at vwtype3.org
Madison, Wisconsin, USA
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