This is the page for my Vanagon. Use the links at the left to look at stuff.


Fri Oct 8 00:50:44 GMT 2004

Replaced the lights on my instrument cluster with LEDs today. I think it turned out well. I have some pictures of the process and the final result.

Instead of using 4 resisters and the original lamp connections I decided to wire them up using 2 circuits, one for the speedo and tach and the other for the clock and indicators. This way I can later add a switch to turn on just one or the other if need be. It'd be nice to illuminate my clock without turning on the marker lights in some situations.

Some playing and experimenting showed that a 39 ohm resister with two of the LEDs in series put me at about the right voltage and illuminated them nicely. I think it turned out well, as the pictures show. I used three 4600 mcd blue LEDs with a 30 degree viewable angle for the speedo, tach and clock. I used one 2600 mcd UV LED for the indicators. Both are 3.5-4.0v LEDs, so the math to figure out how to reduce the voltage wasn't difficult. The LEDs were purchased at Super Bright LEDs.

I ended up using 1/4w resistors because that's what my local Radio Shack had in stock. I would have used 1/2w resistors as they run cooler, but the 1/4w does fine. The LEDs are wired in series.

I'm pretty happy with the illumination. It's not quite as even as I'd like, but then again the incandescent bulbs aren't very even in their illumination either. I looked at using the UV LEDs for everything but even though it illuminated nicely it didn't have quite the effect I wanted. There's also the concern about UV exposure, so I went with the blue.

I found the best way to mount the lamps was to pull the bulb+metal out and then run the legs of each LED through the holes that are left. I then twisted each leg around the holder in opposite directions. This helps to held the LED in place while it's epoxied in, and helps to reduce the stress on the glue joint until it sets. I then soldered on a piece of wire (I used green because that's what I had laying around) and heat shrinked the joint. I tied the ground of the two circuits together and attached them to the ground of a transister on the back of the tach. For the positive, I ended up cutting the illumination wire from the back of the 14 pin connector and splicing in there. I have a quick disconnect at the splice for when I need to remove the instrument cluster. This left me with another terminal for the 14 pin connector on the back of the tach assembley so I could finally ground pin 12 (Oil pressure high, which my '84 doesn't supply) and actually have a working tach.

The installation isn't as clean below the surface as it could be, and I know some people on the Vanagon Mailing List will absolutely hate what I've done, but I'm happy with it. I can adjust the brightness slightly, but it only goes from full bright to slightly dimmer. No way to turn it off, but then again you don't really want to be changing the voltage on LEDs too much.

If you do this yourself, you may consider (as I did) not using a resister because the dimmer will limit the voltage for you. Don't do this. You will end up turning it up one day and blowing the LEDs. In playing with it I did just that. Luckily I had extra LEDs, but now I'll have to order more blue LEDs for some of my other projects I had in mind. Put the resistor in series and be happy with what you can do for dimming.

The following resources were very helpful in getting this all to work.

Wed Sep 29 01:00:07 GMT 2004

Wooo, put in the Z-Bed I got today. Turns out the Z-Bed from an '88 Weekender is 9cm shorter than the rear seat in an '84 GL. I ended up buying small chunks of stainless steel pipe (1/2" diameter) and new bolts that are longer (The seat bolts are 7/16x20, if you ever need to replace one). Use the Z-Bed link on the left to view the pictures I took.

All content Copyright © 2004-2008 Zachary White <zwhite-web @ darkstar.frop.org> except where information is publically available information (EG, radio frequencies, police codes.)