[T3] Emergency Flasher Wiring

Thu Mar 5 14:20:12 PST 2026

Sean, thanks for the corrections. I'd forgotten that the early Type 3 taillight 
bulbs were all single filament.

I had to build a makeshift setup to test  and repair someone's TS relay quite 
a few years ago. I used resistors instead of bulbs for loads, so I couldn't test 
the fast flash feature. That may have been a relay from before '68, so the 
transistors were Ge, which I replaced with modern Si and rebiased each of 
them. Next time someone needs help with a TS relay, I'll try to remember to 
send them to you. (I may still have the drawing I made, documenting the new 
transistors and resistors.) Most of what needed fixing was poor connections 
at the OE rivited connections. Those got soldered.  

If the '66-7 relays were all 9-terminal, how do you explain the 4-terminal 
relay shown in the '66-7 wiring diagram? Were they simply not showing 5 
terminals not used. Yes, I also thought those years used a very complicated 
multiple pin relay, but it seems odd for VW to buy hundreds of thousands of 
relays with features they didn't need.

Now that I'm thinking about it, dual filament just puts two functions into one 
package. It doesn't change what's required from the relay. Don't all years 
have 3 functions with separate filaments dedicated to each function? So I'm 
not understanding what needed to change in the wiring at the flasher relay. 
The wiring back at the bulbs needed to change to accommodate a dual 
filament socket, but that's a trivial change, and only at the bulb socket.

In case I was not clear, for Type 3s, '68s got a new, smaller box with 3 
terminals. '69-70 got exactly the same box, but with the addition of a 4th 
(ground) terminal. Starting in '71, the fuse box got 5 plugin sockets and an  
even smaller, plugin, TS relay was introduced.

Nice video. At first, I guessed that your 4 bulbs represented the 4 TS bulbs 
at the 4 corners of the car, but when you tested brake lights, it seemed like 
all 4 bulbs lit up. Maybe I'm confused and none of the filaments in your setup 
are for brake lights. It certainly looks like you must have incorporated diodes 
to put your 4 filaments to multiple uses (flasher, taillight, brake.) What am I 
missing? Are two of those bulbs dual filament? (I can only make out 2 wires 
to each.) What am I missing?

Jim

On 5 Mar 2026 at 14:35, Sean Bartnik wrote:

> Hi all,
> To address Jim´s last point first:
> 
> Type 3s thru ´69 with the small taillights have 3 separate single-filament bulbs in each rear fixture. Top one is the turn signal, middle is the taillight, and bottom is the brake light. Remember that early Type3s don´t have a reversing light built into the housing. When the big taillights came around in ´70, they combined the taillight and brake light into a single dual-filament bulb, kept the turn signal bulb at the top, and added a reversing light at the bottom.
> 
> During the time when Type 3s had 3 separate single-filament bulbs, Beetles and Buses had a single dual-filament bulb at the rear for both taillight and brake light. Hence the 54/54f circuit for the turn signal relay and why it´s not used in the Type 3.
> 
> Yes Jim the ´66-´67 9-pin relay does also have the "bulb-out" functionality where it will flash faster if a bulb is burned out or missing.
> 
> As far as I am aware there were not 4-pin TS relays in ´66 and ´67. I believe they started in ´68 as that was the changeover from Complex Relay/Simple Switch to Simple Relay/Complex Switch. As far as I'm aware all ´66-´67 (at least for US market cars) had the 9-pin flasher relay.
> 
> Here´s a link to a photo of the correct "simple switch" and bracket that gets used with the 9-pin relay:
> 
> https://photos.smugmug.com/photos/i-pfvrft5/0/L8G2LwZ9nzmzFNdFrwjnbVPPPwKnmFdC4dL2vgRft/L/i-pfvrft5-L.jpg
> 
> https://jerk.smugmug.com/Cars/Squareback/n-V7SJ2R/i-pfvrft5/A
> 
> Here´s another pic of the switch outside of the bracket so you can see the whole thing:
> 
> https://photos.smugmug.com/photos/i-dRtRVWW/0/NBc4x59FXtVgKBnxXLfgBfXjLj6zCMXJwc4CHmrpt/XL/i-dRtRVWW-XL.jpg
> 
> And here´s a video of a 9-pin flasher relay test board that I made if anyone wants to send me their questionable flasher relays for testing :-D
> 
> https://youtu.be/33K5v4yJqy0
> https://youtu.be/33K5v4yJqy0
> 
> As I mentioned all the different variants of the 9-pin flasher are functionally the same though they were made by various manufacturers over the years. Some have a silver case, some have a black case, some have a blue case, and they were available in both 6v and 12v versions. I believe the blue case was the final version of the part and all the blue ones I´ve seen were made by Hella. Some of the other variants were made by SWF and SK. 
> 
> Sean
> 
> 
> > On Mar 5, 2026, at 12:24, Jim Adney <jadney at vwtype3.org> wrote:
> > 
> > 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. 
> 
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Jim Adney, jadney at vwtype3.org
Madison, Wisconsin, USA
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