Wiring Harness, Fuse Panel, Switches and Relay Restoration

[Floating VW]

Ok, here is Part 2: Restoring the Light Switch. . .

My original plan was just to clean up the fuse panel and the wiring harnesses, but one look at that tired ol' light switch and I could practically hear it begging for help!

Now, following true German engineering doctrine, the light switch in an ACVW is way more complex than it needs to be. It's actually three switches rolled into one: 1. Headlights switch (and when I say "headlights", I really mean "dimmer relay"), 2. Parking and tail lights switch, and 3. Dash lights switch. The parking lights, tail lights and dash lights are on a completely separate circuit than the headlights; each with their own separate power wires from the fuse panel. Here's my old light switch (with the wires labeled for your convenience):

As I noted earlier, the power wire for the parking light-tail light-dash light circuit (which is red) is connected to "constant" power, while the power wire for the headlight circuit (which is black and yellow) is connected to "switched" power. This is a poor design in my opinion, which I eventually corrected by connecting both power wires to "constant" power terminals in the fuse panel.

In order to remove the base plate and the slide contacts (there are two of them) from the metal case, you first have to pry back the crimps on the four corners (good luck doing this without ruining them!):

After the crimps are pried back, you'll need to pop the main pin out of the two slide contacts. This is how I did it (side note: the following two pics were actually taken after I had cleaned, repaired and re-assembled the light switch, 'cause I forgot to take pics of most of the disassembly process):

A flange nut on the threaded end and a couple of screwdrivers to pry it outward, and out it popped! Don't be afraid to use a bit of force, that pin is in there pretty good. Once you hear/feel the pin pop, just pull it the rest of the way out, easy-peazy:

After that, the base plate and the slide contacts will pretty much drop out of the metal case. When I got mine apart, this is the horror that I found:

Just look at that dried up, 50 year-old grease and that crusty nylon slide contact! But it gets worse! When I looked at the backing plate for the dash light rheostat to see what condition the rheostat was in, this is what I found:

The rheostat had been burnt away to nothing! I guess I never really noticed because I always keep the dash lights on full bright. And then I looked at the slide contact for the rheostat, and I discovered a clue about what had caused its demise:

The slide contact had got so hot, it burnt the bakelite! It occurred to me that maybe the rheostat was only designed to handle the two small bulbs in the speedometer. It's possible that when I added another gauge or eight to the circuit, it might have been a little more than it could handle:

Not to worry though, I have since replaced all of the original incandescent bulbs in the gauges with much more efficient, red LEDs. The new rheostat should be able to handle them easily.

But first, I needed to get the switch completely disassembled and cleaned. Here's all the bits laid out nice and neat:

To repair the rheostat, I found a piece of heavy, insulated wire that was the perfect diameter and cut it to fit in the backing plate. This will be the foundation for the rheostat:

The actual wire used in a rheostat is made of a special metal called "Nichrome". I'm not sure, but I think it contains a bit of nickel, and maybe even a bit of chromium. . . The only question I have now is, just where the hell am I gonna find some of it? Well, look no further:

I happened to have an old, crappy Chinese fuel gauge sending unit that was just taking up space in my collection, so I put it to good use. The Nichrome wire got wrapped around its foundation (Although I only had enough room to fit about half of all the wire on there. I hope that'll be enough!).

Then, with nicest set of medical grade tweezers I own, and my 3X hobbyist's magnifying lens, I set about separating the wires so the individual spirals wouldn't touch each other (I'll be honest, if you're doing this by hand, this part requires a stupid amount of patience and dexterity!):

And here is the rheostat, all restored in the nice, clean bakelite base plate:

Next, the nylon slide contact gets re-assembled, lubed-up good and sloppy with fresh dielectric grease, and placed on the base plate:

Don't forget to put the two little ball-bearings used for detents on top of the springs in the slide (yep, I forgot to take a picture of that step, too).

The rheostat slide contact is next:

I used the main pin to locate everything, and to help hold it all in place when I put it back on the base plate (but not before getting it sloppy lubed-up!) You'll need to remove the pin before finally assembling the base plate into the metal case.

And here it is, all lubed up and ready to go back together (with the ball-bearing detents in place):

Drop the base plate back into the metal case (this part is a bit fiddly), and then lube up the main pin and push it into the slide contacts until it clicks into place. It helps to keep things from sliding around and potentially getting damaged if you thread that goofy captive nut and the black plastic bushing back into the metal case first, but if you're careful, you can get away without doing this:

Here's a view of the assembled switch with the goofy captive nut and bushing front and center (ok, it's not really a captive nut, but it looks like one), in case you didn't know what I was talking about. And just look at that beautiful rheostat!

Now, to test the rheostat . . . I managed to get enough Nichrome wire wound up in there to give me a maximum of just under 50 ohms of resistance. That turned out to be enough resistance to reduce a single incandescent bulb's maximum brightness by about half. I'd call that a complete success!

To lock the bakelite base plate back in the metal case, I wasn't able to crimp the corners again, but a dab of high-strength JB weld on all four corners worked just fine:

And here is the cleaned, assembled and re-wired light switch (side note: due to the changes I made, the dash light wire is now part of a different harness than the rest of the light switch wires, which is why it's not shown in these pics. The dash light wire can be reconnected to the switch only after the switch is re-installed in the dashboard):

Looks and functions considerably better now, to say the least!

Part 3 is up next, where I tackle the Emergency Flasher switch. . .
_________________
"It's time you started treating people as individuals, rather than mathematically predictable members of an aggregate set, regardless of how well that works."

[Bobs67vwagen]

Very nice work and detail, please keep it coming. Thanks Bob

[runamoc]

[Floating VW]

[Floating VW]

And finally, Part 3, restoring the Emergency Flasher Switch. . .

As with the light switch, the past 50 years have not been kind to the emergency flasher switch. Here it is as I was removing it from the car (with wires once again labelled for your convenience):

This switch, as per usual, is also overly complex, and also has two separate power wires going to it, as well as a redundant ground wire to the chassis. I have an idea why they did it that way, and just like the light switch in my opinion, they ended up potentially creating a big problem in order to avoid a very small and highly unlikely one. And something else that made me scratch my head. . . there was a mysterious, non-OEM black wire that I had connected to terminal 58b a long, long time ago (as noted above in the pic), but it serves no purpose and I have no idea why I did that. More on that, later. . .

Once I got it out, I could see that (also like the light switch), some of the wires had gotten hot in the past, or had been in close proximity to said melted wires. Ah yes, electrical fires. . . fun times!

My first thought was that I could maybe get away with just cleaning the outside of the case and removing the oxidation from the spade connections (after all, the emergency flasher almost never sees any action, so why should it be in anything other than pristine condition, right?):

It cleaned up nice! Unfortunately, compared to the freshly restored light switch, pulling the knob out now felt like the damn thing was full of gravel, so disassembled it was!

To remove the metal case from the base, there are four crimps that need to be pried back, indicated here:

Inside the switch, this is what I found (no wonder it felt like gravel in there!):

Remove the two contact bridges from the slide:

Remove the three springs from the slide:

And remove the two nylon detents from the slide:

If you look closely at the slide contact, you can see the metal tabs that provide power to the little light bulb inside the emergency flasher knob. Ze German engineering is often overly complex, but it can also be very clever sometimes!

Here are the contact bridges, detents and springs all cleaned up:

Now, remember that mysterious black wire connected to terminal 58b? When I examined the wiring diagram, I discovered something very interesting: Terminal 58b sends power to a little light bulb that illuminates the heater levers and emergency brake lever at night. The little light looks like this:

It is supposed to be located in a slot below and behind the ash tray, under the dashboard. I'm not sure, but I think only the Super Beetles got these lights. At any rate, I can only recall seeing them in the Supers; my standard didn't come with one. What's more, when I looked closely at the contacts in my switch, terminal 58b was there, but there was no power source for this terminal. Power would have come in from terminal 54f, but oddly enough, there was only an empty slot where the terminal should be.

Here you can see 58b (it's got one end of a resistor soldered to it), and the spot labelled 54f, but there is no terminal there. (What's more, in my official Bentley service manual wiring diagram, there is not even a reference to a terminal 54f):

54f most likely is meant to be connected to the dash lights as a source of power, with a bridge to connect 58b to 54f when the flasher is not in use. Indeed, inside the switch you can see where the slide contact has a place for a bridge to connect 58b to 54f, but in my switch there is no bridge:

The only reason I can think of for this omission is that the bean counters at VW wanted to save a few pennies, so they didn't install these parts on standard Beetles. But if that is true, why did they bother to solder the resistor to the switch? (The resistor, by the way, serves to provide just a trickle of power to the little light bulb inside the knob, presumably just enough to make it easier to locate the switch in the dark.) With no power to 58b, there is no power to go through the resistor to light up the little bulb. . .

Like I said. . . a mystery. And why I had that black wire connected to it, I'll never know!

At any rate, like it says in the service manual, assembly is the reverse of disassembly, so. . . here is my emergency flasher switch, all cleaned, lubed and rewired:

Let me tell ya', cleaning the last 50 years out of my wiring harness was a slog and a half. I easily have over 75 man-hours wrapped up in this job. . . but it was worth every agonizing minute of it! Everything works so much better now: the switches are like butta', the starter motor hits that flywheel with a vengeance, the head lights are so bright I had to start dimming them again for oncoming traffic, and the turn signal relay now goes CLICK-CLACK, CLICK-CLACK, instead of tink-tink, tink-tink. Even the engine seems to have more power!

It's one of those things where, for years and years, you didn't realize anything was actually wrong until you finally fixed it!
_________________
"It's time you started treating people as individuals, rather than mathematically predictable members of an aggregate set, regardless of how well that works."