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Was headed out one evening, last week, only to find that my Speedster was a daytime only ride. So I ordered a headlight switch and naturally the new switch is too short to to attach to the dash as the dash if about 1/4" thick. Needless to say I need another switch with a longer nipple. Can someone provide a part number that will work ? I guess all Speedsters would have the same issue. This is the old switch. the threaded nipple is 17mm long.IMG_20190822_104020495


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That switch is pretty universal.  If you take it out and wander over to your local NAPA store (or equivalent) I'm pretty sure they'll have one with a longer snout.  If you need a NAPA cognizant part number, I can probably find something in my "Standard" or "Echlin" catalogs, but they should be able to help you right at the counter.

If not, then you can do the reverse-dash grinding that Wolfie mentioned.  I use a Dremel with a 3/16" metal rasp and gently buzz out half the thickness and a circle wide enough to accept the switch body, (If necessary).  There is a Dremel accessory that screws onto the tool body that lets you set the depth of the cutting tool so you won't go through - that's handy to have, too, and prevents what happened to Alan.

I would try for the different switch, first.  After all, if Steele could find one and not have to cut the backside of the dash, you can too.

Last edited by Gordon Nichols

Alan, Thanks. I'm sure your photo is just an example. My switch has 6 terminals and all are used. I'd really like to find a German switch with the DIN numbering. I've sent an email to JPS. I have contacted them in the past and got no response. What's the definition of insanity?

Sacto, The fuse was good. Part of the switch was working. I took it apart and the contacts were all corroded and burnt.

I may be grinding this afternoon. Hate the thought.

That one in the photo doesn't look like anything German I've seen, and if you opt for a VW German one you'll still have the issue behind the dash as those all expect to go into a 19 gauge piece of metal.

You have what appears to be the equivalent of a Standard Auto Parts DS-121 (which is made for 6 volts).  That might 'splain the pitted/corroded contacts inside.

Standard also makes a 12 volt version DS-135.  

Either is a "universal" switch, not specific to any make/model.  Both have that fuse on the back, although the 6V version should have a slightly larger fuse (like a 20 amp).

For sure, NAPA can look those up and see if they either have one or can get one.  They may have dimensional specs on-line, too.  

Jim Gilbert - Madison, Mississippi posted:
Safety Jim Buffalo NY. posted:

You may want to add a relay to the circuit. (Especially the headlight/brights circuit). Corroded / burned contacts indicate the switch can't handle the draw on the circuit.  

There is a lighting relay.


Jim (Gilbert), all of our cars have at least one dimmer (or 'dipping') relay, which switches the output of the headlight switch between high and low beams.

But, if that's the only relay in your headlight circuit, the heavy current for those lights is still being handled by the switch itself, which is what burns out the contacts. At least two additional relays are needed to route that current around the switch (one relay each for high and low beams).

Basically, the output of the dimmer relay is used to control those two other relays instead of going straight to the lights.

Also, a '6-volt' switch is, in theory, preferable to a '12-volt' switch, as it will (in the best of all possible worlds) have more robust contacts than the 12-volt switch. (Insert long, tedious explanation of voltage, current, and power here.)

If this is Greek to you, do some research here or shout out for some help.


- Mitch


Last edited by Sacto Mitch

Sacto, I hear what you say.

Based on the wiring diagrams I have, VW did not have a dimmer relay until 1966 and did not have any other relay in the lighting circuit through 1975. That's as far as I looked.

No doubt, best practice might be to install SPST relays on both the hi and lo beams, but VW didn't find them necessary.

I suspect that the corrosion comes from the fact that the switches are not sealed and water gets in there. Corroded contacts burn. Mine were not destroyed, just corroded up and blackened. If I exercised the switch I could make the lights come on. I did drive this car 700 miles home,  in a thunderstorm all the way, in 2017.

My car was built in 2009 and now has 15k miles.

The headlight switch is rated at 30 amps; same rating as the relays. VW built 20 million bugs at least several million without additional relays.

If the headlight switches are prone to fail or if the wiring harness burn because of the switch, then I'll install the relays. Please advise me if that is the case.

I don't recall this being an issue in the 60's


Last edited by Jim Gilbert - Madison, Mississippi

Jim - You'll note too that every old VW you see on the road looks like it has dim yellow burning candles for headlamps. VW made a high quality switch but skimped on both wire size to the headlights and the lack of a relay - to save a few production Deutsch Marks.  With heavier wiring and relays you'd get full voltage to the headlights (and be able to safely upgraded to whiter light H4 ones) for stronger headlights.  

Image result for h4 light comparison

The wiring to the switch is fine since the switch is just used to provide voltage "to pull in" the relays.  Heavier wiring is added from the battery to the relay (#30) and then the hot side of the relay to headlights (#87).  Since most have the battery in frunk distance is short (a plus).  Be sure to also add an inline fuse.  While there I added a battery cutoff switch to prevent battery drain and act as cheap theft detection.  I used Hella Vision plus "European" lamps with the removable bulbs (Amazon and others have).   There are even more modern LED and HID lights available now but $$$. Here generic wiring diagram -

Image result for fog light wiring diagram

Last edited by WOLFGANG


Jim, you're right. VW ran the headlight current right through the switch and never included relays, mainly (as @WOLFGANG says) to save money.

The problem for us is that it's nearly impossible to find a high-quality switch with beefy contacts made out of real brass like VW used. You can track down some original VW switches or high-quality equivalents if you do some sleuthing, but you'll usually pay mightily for them.

Anything you find in an O'Reilly's, Autozone, NAPA, or on Amazon for a friendly price will look spiffy on the outside, but on the inside where it counts, are only diaphanous slivers of pot metal and alloys that disintegrate when exposed to daylight, air, or heavy breathing.

The normal use of a switch oxidizes the contact points just a tad every time the switch is thrown. This oxidation goes up exponentially as the current through the switch increases. Using relays on a headlight circuit cuts down the current through the switch by a factor of around a thousand, allowing you to get a decent service life out of even a cheapo switch.

The headlight switch on my VS burned out after about the tenth time I turned the headlights on. I was worried about finding a decent replacement that would also accept the knob and bezel that matched the other switches. So, I had VS send me the same switch, but I wired in relays. Six years later, the ersatz switch and I are still happy.



more questions...

What gauge wire?

If LED lights are installed does this really need to be done?

I have a primary disconnect.

I hate the cheesy wiring harness on these cars! All of the dash wiring is junk. 14ga wire to a 3 watt bulb is B.S. In my Spyder, I cut the harness at the the feeds to the dash and built a neat little dash harness that was color coded, actually worked and you could see what every wire was connected to. The 10ga primary wire was the only ones not in the harness. It was all about the size of my little finger.  I may have to do that again.

For the first time, since I've owned the car, the alternator light actually came on prior to starting the engine. I have never had instrument lights in the oil temp/fuel gauge. I'll get it all fixed and then someone will get a reliable go anywhere car they won't have to work on.

I've got a friend that wants to buy it, but I tell him, not yet, I haven't spent enough money on it.



True - if you want LEDs.  With suggested upgrade, the original wiring stays - just cut the 3 prong plug off the back of existing light and pull wire into the frunk.  Hook it to relays so it activates the relay then run the heavier wire to the 3 prong plug from the relays and ground.  Since the battery is right there in nose, it really isn't much wire to run. 

Formula for power(in watts):

P=V×I. V is voltage. I is current

60 watts= 12 x 5, or 6 x 10.

If the wattage of the bulb is the same, twice as much current is drawn through a 6 volt switch at 6 volts. So theoretically a 6 volt switch is designed to handle twice the current a 12 volt one does.

I got an old VW 6 volt headlight switch, and I run LED headlights with no relays. They are bright as heck. 14 gauge wire is good for 15 amps. I might be running 3 amps.

Mitch is right.

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