Carpokes Porsche Forum

The insides of the column switches (turn signals, wipers, cruise on mine) aren't super complicated. It's an incredibly robust switch, with a big Achilles heel. The little "wings" or "tabs" or "ears" on the turn signal stalk break off after a couple decades causing the affected turn signal(s) to no longer stay latched in the on position when activated.

It would be great if someone sold just the affected stalk for DIY repair (vs an entire switch assembly for many $$$). The plastic business-end of the stalk (the part inside the switch body) has complicated geometry and features, though perhaps it would be a 3D printing candidate?

The nylon slider thing is a second Achilles heel, shown here dangling into the hole for the steering column by its pair of springs. It must be involved with self-cancellation. It wears to a point that self-cancellation no longer works (mine doesn't).

Edit: In retrospect, my turn signals stopped self-cancelling only after the first time I "fixed" the little wings. I think the tension spring being positioned improperly created my self-cancellation problem.

I remember seeing in the last six-ish months a YouTube ad (of all things) for a European company that sells a repair kit for that nylon bit, but I have no further knowledge about that kit. I imagine it is more easily modeled for 3D printing purposes.

Edit: I think this is the product. The video on the product page is the one I remember seeing previously. The kit comes with some interesting locking clamp things that hold the stalks in position during disassembly, a handy thing to have.

I'll do a full "What's Inside This" style post in the future. In the mean time, this is mine with the insides exposed. Turn signal stalk is in the foreground.

As you can see, one of the little wings was completely broken. I found it lodged inside the main body of the switch. The other was cracked and broke off when I looked at it funny.

I crazy-glued the broken wings, then encased them in my favorite plastic repair product, described in This Post about the Snowflake Switch. However, the plastic used in the stalk is one of the types that remains chemically unaffected by that repair product. Thus my built up material is NOT integrated into the original plastic and would be easily broken free. Not ideal.

Edit: The following four photos show the main tension spring aligned wrong. The legs of the tension spring belong outside the little wings, not inside. This is addressed Further Below in the current thread.
This repair "works", with a caveat. Whenever I activate the left turn signal, I also end up activating the high beams. Joy. Didn't realize this until I drove the car at night on the Interstate. Whenever I'd change lanes, there were my high beams. Not in a deliberate "flash to pass" sense, but in a "dammit, I've gotta fix my repair" sense.

The clearances inside the switch body are minimal. When the signal stalk is in the left turn position, the built-up material on the upper most wing bumps into one of the spring loaded contact bars, I believe it's the one responsible for flash-to-pass, ironically. I can remove some of the material, of course, which will ultimately weaken the repair.

I know I can buy the entire column switch assembly from the usual places. It seems, though, that only the stoopid wings are the problem.

Has anyone successfully sourced just the turn signal stalk by itself?

Or has anyone developed a printable model of the plastic end of the stalk (the part permanently inside the main body of the switch)? The stalk itself seems to pass through the majority of that plastic part, which is pinned to the stalk at the point the stalk pivots for high beams and flash-to-pass. I imagine the plastic part could be replaced.

Have you looked at this?
https://928srus.com/products/cmbs-repai ... 28-968-986

ROB III wrote: Thu Aug 17, 2023 7:00 pm Have you looked at this?
https://928srus.com/products/cmbs-repai ... 28-968-986

Thank you for the link. Yeah, that's a lot like the European YouTube ad I saw, complete with the fixture clamps to hold the stalks during disassembly/reassembly. It would address the "self-cancellation" problem, but not the "broken wings" problem (which is the bigger problem).

Maybe there's some other German 80's car that uses the same turn signal stalk? Not the same switch/combo switch assembly. Just the same stalk. Hopefully for less dinero than the 944 combo switch from Porsche. Disassemble whatever that one would be and put the stalk into the combo switch?

I had the self cancellation problem only when turning one way. A fellow 944 brother clued me in to a fix: wrap the tab on the steering wheel with aluminum tape. This increases the size of the tab by ~ 1mm (with 5-6 wraps) and allows it to trigger that white piece that is hanging in the center cavity in your first picture. Worked for me.

I have another problem my windshield washer switch not working. I have yet to pull my stalk assembly apart like you did...was it difficult? It looks like it is riveted together, so I was hesitant to split the thing open. How does it go back together?

Aaron_N wrote: Fri Aug 18, 2023 6:21 am I have another problem my windshield washer switch not working. I have yet to pull my stalk assembly apart like you did...was it difficult? It looks like it is riveted together, so I was hesitant to split the thing open. How does it go back together?

It is riveted together and not difficult to disassemble. The rivets drill out easily. The internals are spring loaded, so it will want to fly apart. I used little bar clamps to hold the housing body together while removing the rivets in order to control the disassembly to some degree.

It is fussy to reassemble, given the springs and stalks. I used little screws with a tapered head instead of rivets. I chamfered the holes in the metal plate so the screws sit flush and a drop of crazy glue in the hole to help prevent the screws backing out.

However, you might be able to get your washer switch to work without disassembly. Remove the assembly from the car and spray good contract cleaner into any opening you can. I use Deoxit for electrical contact cleaning.

I hate to do this, but I have a post over on Rennlist, on the 928 forum, about what I did for this. Essentially, I replaced the broken plastic tab with a small aluminum piece. Others have gone the same route, and been able to use a small screw to anchor the metal tab to the stalk, but I felt that was a little risky, and that the (quite strong) spring would do enough of a job to keep things together appropriately. There are some good DIYs on the 928 forum about this issue.

So far, things are working well on that car with that repair.

I can get you the link, if you'd like, but I'm admittedly self-conscious about sending folks over there, from here.

Cheers

@Aaron_N : Indeed, you have to drill out the rivets and then use screws to put things back together. It's not that bad, but it did make me pause.

Cheers

Zirconocene wrote: Fri Aug 18, 2023 9:30 am I hate to do this, but I have a post over on Rennlist, on the 928 forum, about what I did for this. Essentially, I replaced the broken plastic tab with a small aluminum piece.

Ah ha and eureka! I found your post by searching the RL 928 forum for "turn signal stalk repair" (in quotes).

It seems I have not correctly interpreted how the quite strong spring is supposed to fit in relation to the "wings". When I disassembled my combination switch the first time, the turn signal stalk escaped and hit the workbench and dislodged that spring.

I made a guess as to how it must sit, reasoning that the little weak flimsy brittle plastic wings couldn't possibly sit inboard of the quite strong and uncompromising spring. Oops.


The first pic below was taken immediately upon first disassembly. The spring is already dislodged from its proper position due to the "boing factor" of the disassembly.

I know what i'm working on today.

usury wrote: Fri Aug 18, 2023 8:27 am

Aaron_N wrote: Fri Aug 18, 2023 6:21 am I have another problem my windshield washer switch not working. I have yet to pull my stalk assembly apart like you did...was it difficult? It looks like it is riveted together, so I was hesitant to split the thing open. How does it go back together?

However, you might be able to get your washer switch to work without disassembly. Remove the assembly from the car and spray good contract cleaner into any opening you can. I use Deoxit for electrical contact cleaning.

Going to try this next, I hope it works! Thanks

I've been working on a CAD model of the turn signal stalk plastic base click-o-matic contact tension spring contraption with wings (don't know what its real name is).

Floating Wings version
Well, kinda floating. There is some separation between the "wings" and the main body in the form of a narrow channel.
Integrated Wings version
Much chonkier attachment of wings to main body. Similar to the aluminum plate approach described by @Zirconocene in their previously-referenced RL post.
I don't know how suitable this would be for 3D printing. Lots of covered void spaces and overhangs. I don't have a 3D printer, and what little I know about it comes only from YouTubers talking about their experiences. I also don't know how to design models suitable for 3D printing.

This model is based on direct measurements of my probably-worn-and-who-knows-how-out-of-tolerance actual part. Plus, both of my "wings" were broken off, so I reattached them with crazy glue and made "best guesses" as to their alignment (by referencing other photos of disassembled column switch assemblies). I'm good with a vernier calipers, and even better with a digital one. Still, some of this stuff was tough to measure. I used a nice set of machinist's drill bits as pin gauges to determine tricky dimensions.

I'm using FreeCAD (v0.20.2). It has native Linux support, but it is kinda buggy and has a tendency to hork-up sketches and their extrusions based on previous geometry when editing that previous geometry changes the number of faces/edges. The software seems to renumber faces/edges internally and doesn't update dependencies with the new numbers, as best I can tell. It's a real pain to clean up the dependencies.

However, if people are interested, I'd be willing to post the STL files.