Lights -- interior, incl. instrument and dash lights


New member
Dear Capt. Mike,
Would you be so kind to explain me how to to bypass the dimmer switch on my 1988 Westfalia Joker ? I am not able to figure out this from Bentley manual. The printed circuit is OK, I have checked it with a separate battery after I removed the instrument assemby. Something must be wrong with the combined light-switch/dimmer, because every time when I switch on the light and turning the dimmer, a fuse goes off.

Capt. Mike

If you are blowing fuses everytime you move the dimmer switch, it sounds like you have a short either in the dimmer switch or between the switch and lights. Disconnect the dimmer switch as shown in circuits 104 & 105 of the Bentley 97.130. Using a volt-ohmmeter, check the circuits from terminal 56a & 56b to the lights for grounds.

If, however, you are talking about the rehostat for dash lights and the light switch itself, they are a fairly common failure with age, especially since most keep the rheostat on the same spot and it eventually burns. The "Exterior Lights . . ." topic covers that.
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New member
Thanks Capt. Mike.
I am talking about the rehostat for dash lights and the switch. The headlight switch working fine in this combined switch/dash-light dimmer. Should I chnage the whole or anytning to ceheck ?
You have mentioned somewhere that there is way to bypass this rehostat.

Capt. Mike

The rheostat part of the headlight switch is built-in; the whole switch must be replaced. Caution: there are two switches and the changeover VIN # listed in the parts fiche is not necessarily accurate. Remove yours and replace by part number from the switch as most electrical parts are non-returnable.


New member
Fixing up dim instrument panel lights
I was always a bit annoyed by the super dim instrument panel lights. While the faint warm glow of these old lights is kinda cozy, it just wasn't what i wanted. So I replaced them with LED's. I got some bright blue LED's and put those in. The only problem is that you need to pull an extra wires to ground the LED's. And you need to put a resistor in serial with every LED. So now I have nice contempory blueish backlights, which also fits much better to my new radio!


New member
My automatic transmission console does not light up. I suspect it is the LEDs. Can you please let me know how to acces these LEDs. How do I remove the cover? I have a Bently but cannot not find it.



New member
I have a 90 camper. I finally did manage to find it. I lifted it up with the flat blade screw driver. This is where my problem of the dash lights not working was. One of the LED wires was getting shorted on the gear shifter.
Now I have to get my gas guage fixed.


Here is an odd one,,,

Driving my syncro in to have the starter changed, I turned on the headlights. The result was, it killed the tach and the digital clock. Further investigation reveals that if you turn on the lights, the dash lights don't work, the headlight dimmer doesn't work, (Lights on high beam) one low beam out!. Flipping ghte dimmer lever makes the oil pressure light glow dim, and the high beam blue light does not come on. I don't think that the dimmer relay is clicking either. I haven't looked very far yet, but any thoughts from smarter people than I would be appreciated. I'm thinking I must have a ground problem somewhere. I did replace the radio recently and made up a new ground for it. I'm wondering if somehow the light circuit grounds through the radio ground. (I'll have to peruse the wiring diagram in the Bentley.)

Any thoughts?


A follow up,,,,

After doing the starter we started looking for the gremlin in the dash. It all sort of defied all logic. Cutting the wire from the light switch made the gauges work properly, but then the temp light would stay lit. All the voltages checked out, including the integrity of the ground. Finaly at the stump point we added a redundant ground and presto, everything returned to normal.

It seems that even though the ground was "good" with no load, once it was loaded it couldn't carry the load. It was trying to pick up a ground through the light bulb in the dash lights.

The long and short of all of this is,, when you are looking for electrical gremlins, don't forget the grounds. Many seperate circuts share a common ground and a weak one can cause all kinds of havoc. The ground problem I had with the radio earlier was probably indicative of this ground failing. While the radio and the inst. cluster have seperate ground wires, I suspect they come together somewhere.

To finally fix this I just added a new ground wire back to the grounding tree behind the dash. I never did bother to trace them both back to thier grounding lug.

Once again thanks to Harmony Motor Works in Bellingham for working this through with me.


Capt. Mike

Replacing dash light behind heater control panel, late model Vanagon.

Murphy's law -- I had to replace the electrical end of the ignition switch and when all was done, the light for the lever and fan panel didn't work.

The Bentley isn't super intuitive about replacement. Here's the procedure:

Pull the fan switch straight out & off with a padded (rag) pair of pliers.

Remove the 4 levers by pulling directly out. Center in panel before pulling. This may be quite difficult. They are held by a detent button on the metal arm. You might silicone spray in there first, which should not harm the lever mechanisms. Notice there are two types of lever ends, one has side bumps. Also note which way they offset going back in!

The panel is then held friction fit on plastic pins left & right. It should pull straight out -- if prying the ends, don't get cocked far off straight because you could break off the plastic pins.

The light bulb-holder slides into a socket on the panel back. Remove the two wires and then the panel.

The holder comes out of the panel socket easily, but the bulb does not come out of the holder. I tested with an ohm meter to be sure it was the bulb first, then ended up breaking the bulb to get a grip with a small pair of needle nose pliers. It pulls straight out. I just couldn't get enough friction & grip with my fingers.

The replacement bulb is P/N N017 751 2 and is the slide-in style with the contact wires folded up the side of the base. Needless to say, it doesn't work all that well since the contacts in the bulb-holder are covered with plastic except the top ends. I finally achieved contact by slightly bending the wires on the bulb over the center of their respective sides. Of course each time you put the bulb in to test, you face the problem of getting it out again if it doesn't make contact. I spent more time on that than on the main task. Buy at least 2, you could easily break one in this excercise of futility and have a spare if you don't. I did silicone the bulb holder, which is OK if you don't get any on the bulb head itself.

Finally the ohmmeter said I had contact. I then hooked up the wires to be sure I had light. Before putting the panel back on the dash, the wires have to clip into the bracket on the back of the face plate to keep them from being in the way of the lever movement. Also, they have to feed back through the hole in the dash itself so as not to have excess behind the switch panel.

Once the panel is reinstalled, install the lever ends in the reverse order you removed them. I found it helpful to have a small screwdriver at hand to hold the lever up or down a little while I started the lever ends on as they rarely line up exactly with the slot opening. Have the lever in the center when pushing the ends on; do not over push beyond the detents. Move the lever to one end or the other while you do the next.

For those of you that just ripped out the lever ends first, hint: The top lever is without the knob bumps and the offset is up. The 2nd, with bumps, offset down; 3rd without, up; 4th with, down. When you're finished they should go all the way to the end if the panel slot without the lever knobs hitting the panel.
87 Westfalia, with a brand spankin' new 2.4 Waterboxer from GoWesty!

Had a really interesting problem this week... Right front turn signal went out. I found out via the rapid flash & click of the instrument panels turn signal indicator & relay from the fuse panel. This was no big deal. Went to my local VW dealer & got a couple of spare bulbs to replace. When I opened the lens to change out the bulb, I found that the bulb connector was very badly corroded. I then went back to VW, and ordered a replacement for both front turn signals, as I figured that if one was nasty, the other prob'ly was too. In the meantime, I still wanted to drive my beloved van legally, and so replaced the bulb into the corroded connector, after cleaning it up a bit with a dremel. The signal worked, and life was good! Then, a couple of days later, my new connectors came in, so I pulled both lens assemblies, and swapped out both connectors - only to find that now my blinkers weren't working. I would get random flashes from the cigarette lighter surround, the license plate light, taillights, etc. It was as if gremlins had suddenly decided to inhabit my electrical system! (Fancy that in a VW...) After much swearing & troubleshooting, I finally traced the problem down. VW had given me 2 different replacement bulbs - a monofilament, and a double filament. I swapped out both bulbs, with the double filament version (one for the parking light, the other for the signal), and now everything is just peachy again.

Good times!


Capt. Mike

Although many of the new bulbs have weird bases and sockets, most of those with the bayonet round base (2 side nubs; push & turn ~30°) that are dual filament will have two bottom contacts. Thus easy to chefck before inserting.

Having the contacts correctly aligned with the socket is important, otherwise you have the extra bright light all the time and the dim one is the added filament. Most of the sockets have the bayonet nubs staggered to prevent this, but it's still possible. I'm sure you've seen that on cars running down the road.

Since the socket is also the ground, the contact between the bulb and socket can create an electrolysis corrossion. Several of the tool manufacturers have nice little clean-up wire brushes sized accordingly. But you can find some excellent cleaner chemicals at electronic supply stores. Some clean contacts, others lubricate, still others both. Versions specifically compounded to disolve corrossion are available. They are electrically inert so don't affect the connection. In this day & age, these are not going to attack plastic or phenolic parts (unlike some of the "electrical cleaners" in the auto parts store). Do check the condition of the contacts in the socket; they are soft and often get gouged or damaged. They can be sanded or brushed smooth again. If they are rough or burned, they can cause electrical failure or create a problem when changing bulbs. Having the glass break because the base won't turn is no fun.


New member
interior lights, alarm system, battery drain

Dear Capt Mike- help w/ correct place for this:
My wife has cancer. So now I have parked the Westy (1990, 2.1 L, I own Bentley, 10 mo old Interstate Battery, runs great) for several months, and with infrequent use- the battery drains dead. I have 248,000 mi on the van- and never had a battery drain problem- even when parked for a mtn trip for 2-3 months. The clock is smeared black-LED wasted- maybe drain there.
My drivers interior door light now comes on when I open the passenger door- but not when I open the drivers door. When Drivers door opens, alarm click-click behind drivers headlight sounds off (not alarm- but the click-click of the relay).
I disconnected the battery hot terminal for the alarm system. Same problem. I disconnect the extra brown ground. Click gone, but still no drivers light, but the pass light does work opening and closing the door. Battery still drains. I figure- now disconnect the clock. (?)
But why is the relay clicking? Why no interior light on drivers side?

Local VW shop said radio has short- they bent it out of the dash (ugh) pulled wires (ugh) but the battery still drains, alarm relay still clicks, drivers interior light still no work. IDEAS? Alarm systems are not really covered in Bentley.

Capt. Mike

The interior light over the driver's door should come on with either door. The circuit is simple -- the light is live at all times and the little button in the door jamb completes the ground. They can usually be corrected by simple cleaning and resetting.

My '90 Syncro does the same -- battery goes dead in 2-3 weeks of non-use. And I do mean dead -- not even a click on the starter. Unfortunately, things like the alarm, clock & memory for the radio apparently are enough to run it down even when everything seem to be working right and/or disconnected. Don't know what else it could be so I live with it. It doesn't seem do be significant to affect it when started regularly, even a week or so apart. I think in your case, I'd go for one of the little Battery Tender chargers. I don't favor them for permanent solution (see "Care & Feeding of Batteries" in the TIPS forum), but I'm going to even consider it myself. I don't drive my Syncro much anymore now that we've inherited my mother's Jetta TDI. Power, mileage, good A/C, & service costs are hard to ignore so mine gets it's main use during hunting season and bad weather so sits idle much of the rest of the year.
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New member
I had a small victory with my dash lights that I thought I would share. The rheostat/dimmer was acting up, so I knew it was the source of the trouble. They flickered from time to time, and then would go out, but twiddling with the dimmer wheel would bring them back to life. Then they just went off and stayed off.

I removed the switch and inspected it. The dimmer is pretty basic, with a coil of wires and a conducting wand that passes over said coil. The wand on mine had lost its tension, and did not make sufficient contact with the coil. By simply bending the wand with tweezers, we were able to add enough tension to bring it all back to life. Maybe I'll get another 30 years out of it!

If your dimmer wheel does seems to spin very freely, with no tension or apparent friction, your contacts may be losing tension. If your instrument lights go off, try this repair.

Incidentally, I also installed headlight relays recently, which I agree takes a lot of load off that old switch, and should extend its life expectancy. I also noticed an improvement in headlight power.