Date:         Wed, 3 Apr 2002 17:01:46 EST
Reply-To:     FrankGRUN@AOL.COM
Sender:       Vanagon Mailing List <vanagon@gerry.vanagon.com>
From:         Frank Grunthaner <FrankGRUN@AOL.COM>
Subject:      Comments on LED Wiring, was Re: LED's on the dash
Content-Type: text/plain; charset="US-ASCII"

In a message dated 4/3/02 10:32:03 AM, labusch@arczip.com writes:

<< If you are serious (really did what you described), have you done any
writeup on these changes? If you have and could post them it would be
helpful to some of us that might want to do some or all of the same.
Wiring details, routing, etc.

If this was just another 'wish list', you forgot the 'Top Is Up Dummy'
light! >>

Aah, you of little faith. To suggest that I would share my wish list with
this group of vendor bashers, vegetarians and idle stumblers! I'm wounded to
the quick! I don't have time for an extended dissertation here, but a few
quick notes:

1). The key here is to recognize that a wiring harness is just a bundle of
color coded wires. It can be cut, tapped  and rerouted at will. The printed
circuit foil is just a roadkill version of same. Oftentimes easier to trace.
2). The biggest hassle is to access the backside of the instrument cluster
just below the idiot light window. I drilled a set of holes, then dropped in
single LED socket holders (after squaring them off to drop into the recesses
in the cluster plastic. I also used thin flat wire to bring all the LED
addressing leads out along the side of the clock module.
3). I have a set of pictures taken about a year ago when I was rewiring my
stereo setup. There cover views of the front of the clock/idiot light cluster
as well as my location of the AF gauge, the Vacuum, CHT and EGT gauges, the
compass and the voltage, cooling system pressure, oil temp and pressure
group. At the time of these pictures, I had not yet replaced the wide black
strip between LEDs with an Icon strip. In fact as I redesign the gauge system
for the 3A Turbo, I will be changing this since I'm making an extended dash
instrument cover. In the new design, I am mounting a bank of gauges and a
fuel/trip computer above the existing spedo/tach group. This set of images is
about 3.5 M stuffed with Stuffit. The images are JPEGs. I probably have a
lower resolution set modified by David Bierl (sp), on the home computational
device. If your emailer can handle em, send me an email request.
4). All the LEDs I use are for 12 V applied so voltage dropping resistors are
included in the common lead.
5). Correction. I said I monitored when the fan was on. False. I'm lazy and
didn't feel like putting together a current monitoring circuit, so (more
correctly), I monitor the state of the fan relays. I tap the line to the fan
for the low and high speed circuits. So when the low speed fan is triggered
(has voltage applied) I have a lit LED!.
6). For the turn signals, I just tapped the line from the turn signal switch.
Bentley decodes all these colors nicely.
7). As I recall, the triggering polarity for the idiot light LEDs was reverse
of rational (I think they switch ground instead of power), so as needed, I
used a set of micro (low current) 12 V relays as needed (about 25 cents each
at C & H Sales - Pasadena - my favorite govt. surplus junkyard).
8). I think I used a small voltage amplifier on the refrigerator burner on
light, because the voltage was surprisingly low.
9). Fog and driving lights are power applied taps at the fog light switch.
10). The new icon group in the idiot light cluster was made with the MAC,
laserprinting on transparency stock. Took three replicate layers, each
aligned above the other to get the final optical density. Used a train icon
for my cruise control symbol.
11). I have a 32 twisted pair bundle/cable/bus running from front to back in
the Westfalia, just for sensing issues.
12). Sounds harder than it is!

Frank Grunthaner