Vanagon – hacking switches to add LED lights

A couple of kludges here, adding LED lights to the headlight switch and the rear defogger switch. I did this to bug my friend Simon 🙂

First the headlight switch. There are two kinds of switch, one has a white plastic insert in the hole on the back of the switch and one doesn’t. It’s the former that can be illuminated.

Here is a view of the back of the switch removed from the connector and you can make out the white plastic in the hole. Disregard that purple wire soldered to the spade connector, that was a failed experiment.

For a more professional way of installing a lamp into the switch look at this Samba thread. I didn’t have the little bulb holding clips shown in that thread, so I did it a little differently.

Now switch focus from the switch to the connector with all the wires coming out of it, sitting there in dash.

I used a bare bulb white LED and a resistor. The LED fits nicely into the hole in the switch connector and I opened the slots at the base of the hole with an awl so the legs of the LED would fit through. I then could push the LED into the hole and the legs of the LED poked through the other side. I soldered a wire onto one leg and a resistor onto the other. I forget the resistor value at the moment, but you can read the code in the picture. I soldered the other end of the resistor to the black and yellow wire coming into the switch connector. That wire is connected to the X-relay current path, so it get power when the key is on. The purple wire grounds the LED through the handbrake on warning light connecter, the brown wire on that white connector in the picture.

I chose to power the LED from the X-relay track for the reason that I wanted the headlight switch to illuminate when I turned the key, not when I switched on the lights (which seems rather redundant).

Here is the LED powered before the connector is mated to the switch.

Seems pretty bright. The icon on the switch is noticeably lit up even in daylight. I’ll see if it is too bright tonight.

The next kludge is the rear defogger light. There are two tiny little bulbs inside the switch, one to light up the tiny amber dot on the side of the switch when the defogger is on, and one to light up the switch when the headlights/running lights are on. The latter was burned out in my switch. I pulled the back of the switch off (careful, springs and one ball bearing inside), and I put in a LED instead of an incandescent bulb. During the process I broke a little plastic shield that prevents the switch illumination light from also lighting up the little amber dot. One of the pictures shows the shield off, I glued it back on before reassembly of the switch. The leads of the bulbs in the switch are connected to the brass trace by simply being tucked under them. You can pry the trace up and slip the lead of the new bulbs under, then press the trace down again. The resistor can be tucked into a recess in the plastic. I have the negative leg of the LED tucked under the brass at the bottom, which is the “31” spade on the switch, and the positive leg curves up (covered in blue heat shrink) to tuck under the brass at the top, which is the “56b” spade (powered by the headlight dimmer switch).  The switch goes back together pretty easily.

  1. #1 by Simon on June 9, 2011 - 7:25 pm

    Geez – I’m jealous!

    OTOH I won this on ebay today…

    Not sure the link will open but it’s a lighted porche foglight switch… winning bid was $2.99 🙂

    • #2 by albell on June 10, 2011 - 7:48 am

      3 bucks! good deal. Curse you Simon, now I have to try to make my switch light up. Its is wired for a bulb, but perversely it lights up only when the switch is on.


      • #3 by Old Fussbudget on June 10, 2011 - 7:53 am

        ‘Cos you’re using the 30 terminal for the load instead of the supply…

      • #4 by Old Fussbudget on June 10, 2011 - 7:58 am

        That’s assuming the light is meant for illumination and not as an indicator, of course. And implies that it would have to be sourced through ignition or headlight switch so the bulb doesn’t run all the time.

      • #5 by albell on June 10, 2011 - 8:41 am

        I want the switch icons to be lit up when key is on. The little amber dot on side of switches will be my “switch is on indicator”. But I am not sure if the bulb in my fog light switch does double duty…


      • #6 by albell on June 10, 2011 - 8:38 am

        The fog light switch I have is hard wired to light up only when it is turned on. There are 3 spades on the back – power in and two power outs. The light power is a built in trace to the bulb holder spot. It gets power when switch is turned on. Simon’s fancy schmancy new switch has additional spades on the back for the bulb to be lit independently.
        I have my switch power input wired so that it only gets power when key is on. I could cut the built in trace and then jump it to the power in spade, by-passing the internal switch so that the light comes on when key is on. I’ll look into today and post some pics to make this clear.


      • #7 by Old Fussbudget on June 10, 2011 - 9:16 am

        Not sure what you mean by power in and two power outs…should be a terminal to one side of the light, a terminal to switch+other side of light, a terminal to switch. If the light’s an incandescent then you choose whether the dedicated terminal goes to power or to ground, and you choose whether to use the common terminal for the supply or load terminal of the power circuit.

        You can choose always on (common terminal+, dedicated terminal gnd); on with switch on (common terminal load, dedicated terminal ground); on with switch off (common terminal load, dedicated terminal to +12v).

      • #8 by albell on June 10, 2011 - 9:44 am

        Just wait David my man, I’ll post pics of the back of the switch….

        (3 spades on the back, one power in, 2 out – one for the front fogs and one for the rear red fog – 3 position switch, off, front fogs, rear fog)

        no grnd spade on the switch, there is a ground tab in the bulb holder though,


      • #9 by albell on June 10, 2011 - 9:56 am

        Ok David, here is the back of the fog light switch. Much different than the one SImon linked to. See the “+” for the power in? and the 2 terminals 83a and 83b for the fog light out power. See the trace that only is powered when the switch is on? The bayonet type bulb holder is coming out right at you, the ground tab on it visible.

      • #10 by albell on June 10, 2011 - 10:49 am

        I should have realized this before, but I took the switch rocker off and I can see the light in the back is only for the amber dot. The icon does not have a translucent white plastic backing, darn.

  2. #11 by Old Fussbudget on June 9, 2011 - 7:32 pm

    But mate, you’ve solved the two non-problems and left the problem! Herr Doktor Hans the Ingenieur and his Auszubildende made the clear decision that if you don’t know where the light switch is, sucks to you, don’t drive at night. And the defogger switch symbol lights up fine.

    It’s that stupid little amber dot! Even if it weren’t hidden behind the steering wheel, it shines a skinny beam of amber light exactly where you’re not. Abscheulichkeit! In Stand setzen! Veröffentlichen! Schnell, schnell!

    • #12 by albell on June 9, 2011 - 7:40 pm

      no, i have it so the headlight switch lights up when the key is turned!

      X-relay powered


      • #13 by Old Fussbudget on June 9, 2011 - 7:51 pm

        Ach! Dreadful. That’s a whole extra 0.010 amps whenever the key is turned. And worse, it might enable some Zylinderkopfschraube mit Schlitz who would otherwise be prevented (and rightly!) to drive at night and the highway verwüsten. 😉

      • #14 by albell on June 10, 2011 - 12:23 am

        I just got back from town. Driving in the dark and the light on the headlight switch is great. I had to look up “schraube”, forgot the meaning. A “drunken cylinderhead screw”? 🙂

        what we really need for them is a light on the ign switch keyhole that goes on for a while when door opened 🙂


    • #15 by Old Fussbudget on June 10, 2011 - 3:44 am

      Slotted cheese-head screw was how my source had it.. 🙂

  3. #16 by Old Fussbudget on June 9, 2011 - 8:02 pm

    Ok, I’ll have done with …but it was fun.

    der Zylinderkopfschraube mit Schlitz. Oder Narragansett.

    • #17 by albell on June 10, 2011 - 7:44 am

      everyone knows “schlitz” is a beer 🙂


      • #18 by Old Fussbudget on June 10, 2011 - 7:47 am

        Around here, so is Narragansett. 😉

      • #19 by albell on June 10, 2011 - 8:29 am

        I thought ” Narragansett” was a brand of muscle relaxant.

      • #20 by Old Fussbudget on June 10, 2011 - 7:49 am

        So when are you going to deal with the stupid ‘On’ indicator, Mr. Change-the-subject? ;->

      • #21 by albell on June 10, 2011 - 8:30 am

        you mean the little amber dot on the defogger and fog light switches? ab

      • #22 by Old Fussbudget on June 10, 2011 - 9:17 am

        I do. On mine the angle of the beam intersects the medallion on the steering wheel. Just right if I’m walking outside and pushing.

      • #23 by albell on June 10, 2011 - 9:45 am

        The whole “line of site to the instruments” subject was completely botched on the vanagon.


Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s

%d bloggers like this: