Let's start this section by saying that I know a lot more about automotive
I did 12 months ago. This is one area that I wish I could just
start and keep going until finished. Using loads of forum
suggestions, some wonderful assistance from Garage Freak and.... a few of my own
ideas, I managed to design a schematic. It started with a Painless
Harness but basically scrapped everything but the fuse box..... used relays wherever possible,
went with better wire, solder spliced, covered all joints with double wall heat shrink tubing, integrated a 37-pin
AMP master dash disconnect, mounted everything (drilled and tapped) possible on a hinged
lower dash cover, and will cover all wiring using a high quality nylon loom I
got from Waytek Wire. The schematic is pretty cool.
Although this took an enormous amount of my time, I like to
look at this as one
of those things that sets my car apart ...... hmmm.... I
wonder if you get one of these if you buy a Shelby or Superformance?
As of 1/12/07 everything is connected .... every wire
had a mate - I am still a little surprised at that. I have tested everything (in as many combinations as I
could imagine) with the exception the starting system. Once I
receive my CSR t-filler (hopefully this weekend).... this car will finally come
Setup: I used a fused relay to power the
fan (highly recommended) and added a toggle switch in case I wanted the fan to
come one before the thermostat decided. While adding a quick disconnect
is not as necessary as say the headlights .... I decided to keep with the
theme and add Weatherpacks for any external device. In general
they allow a nice robust way to disconnect devices and they are built to
withstand outdoor conditions.
Even though I'm using a carburetor, I installed a fuel
shutoff safety switch. It will stop fuel flow in case of a rollover
by preventing power from reaching the fuel pump.
I also added a manual
switch to turn the fuel pump on/off. Kind of a "cool" factor but also
adds a small level of added anti-theft security.
Note: The fuel safety switch is a very
simple device. When it is upside down, a ball bearing pushes the switch
open. The switch can only only be reset (closed) when it is in the
upright position and weight of the bearing is off the switch.
Ignition: For those of you that spent a little
more than you should have on a custom DUI like mine (which includes a custom
distributor curve to match my engine profile).... here is how I wired it. |
Circuit: A few guys
have asked about how to wire a start button. I
am sure there are many ways but this is how I did it.
- With this setup the key
must be in the "Run" position before the start button is
- The "Crank" position of
the key is not used (or wired). You can turn
the key to "crank" but nothing will happen.
- The key must be tuned off to
disable the ignition (stop the engine). (The start
button is a start button only .... not a start/stop
Disconnect: I am sure that there are a few
ways to wire this circuit.... this is how I did it ....and includes the
- remote battery terminal lugs
- the alternator and battery will both be shut down
simultaneously - required for some tracks
- a 100A circuit breaker is protecting the system
from alternator spikes
- a 60A circuit breaker is protecting the fuse box
Circuit: This circuit is a culmination of
a bunch of great forum ideas:
- VW latching relay and Flash to Pass relay are
controlled by the momentary button on the end of VW turn stalk.
a) With the lights off, the high beams can be flashed
as quickly as you can push the momentary button.
b) When the painless headlight switch is used to turn
on the low beams, the high beams can again be activated by pushing the
- Since pin 56 and 56B are tied together, the
low beams remain on when the high beams are turned on. (more light)
- a separate high beam relay is used to take the load
off the switch and reduce heating issues that other members have noted with
the painless setup.
- the rheostat on the painless switch is used to dim
the dash lights
- to keep the front park lights on when the
headlights are, connect both the parking light wire and tail light wire
together and attach to the tail light terminal of the Painless switch.
all fits: Not a lot of room left though. If
you are curious... I created a separate section titled Dash Wiring.
Spared no expense here...Horn, High Beams, Flash-to-pass, Dimmer, Starter
(for button or key starts), Fan, Fuel Pump and two extra (a total of 9).
Also used relay "connector" boxes to make wiring much easier (and more
Disconnect: This 37 PIN Puppy took days to put
together and solder. It is cool and serves a purpose but...|
Manual Reset Breakers
replace Mega Fuse: First Step - get rid
of Mega Fuse. Instead I used a 100A manual reset breaker to
protect the fuse box/harness from nasty things that may come from the battery
and/or alternator. Then I used a 60A manual reset breaker to
protect the fuse box/harness from spikes generated in the main fuse box power
Diodes & Secondary Circuit Breakers:
I used Radio Shack 6 amp "rectifier" diodes
#276-1661 to restrict current flow. These diodes also have a 400A surge
Because they are sensitive to heat, I decided not to solder but instead use
some bus bars as my connection method. Turned out pretty clean.
I also needed a few extra circuit
breakers so I added 2 (20amp) and 2 (30 amp). Notice that I also used
the circuit breaker mounts and protective covers.
|Russ Thompson Turn
Signal: To keep with the theme of an
easily removable dash I used two leftover WeatherPak connectors (3 pin & 2
pin) to provide an easy disconnect between column mounted turn signal and
harness. I am using the button on the end of my turn
signal as my flash-to-pass switch.
I have included a switch to manually override the cooling thermostat ... just
Passenger and Driver have hi/low switches for their seat heaters.
Passenger and Driver have switches for the Cobra Earl cooling fans.
I mounted mine behind the passenger seat. I
used nylon loom and red electrical boots to protect all high current
wanted to learn so here he is cutting wires and soldering WeatherPak
connectors for the tail-lights. He did a great job!
Added switched lights for engine compartment,
trunk (click image) and one for driver and passenger foot box area (total=4). This
little baby caused me a bit of electrical grief. One of the wires
passing through firewall somehow got chafed, touched the firewall and when the
circuit was energized, the fuse would blow.
Sensor: This is what an electronic 8 pulse
speedo sensor looks like (from Classic Instruments) |
Wiring : Loads of great information on the
Daniel Stern Lighting
website. I chose to run 10GA wiring from the relays to the
headlights (including ground). Overkill ...absolutely ...
but I since I plan to run 7" Cibie's the extra capacity can't hurt.
Note use of shrink tubing to finish the job properly. You'll need
MetriPack for this application.
101: Solder splicing... Step #1:
Step #2: (click on picture) carefully fit wires
together and then twist.
Soldering 101: Solder
splicing... Step #3: heat wire from bottom .... let "wire- heat" melt
Step #4: (click on picture) note solder has
101: Solder splicing... Final
Step: add heat shrink tube
Hard to see with my poor photography but I went a
little crazy with the heat shrink. To make everything look nice and
uniform, I even covered the connector shell with just a little hanging over
the typical plastic loom and replaced with professional
grade... split nylon loom. Used about 100 ft of 1/2"
and 50' of 3/4". This stuff is awesome - but
All the wire harnesses coming
together and entering dash area (from passenger side).
N.B. Pardon the dust
on the polished panels
|I personally like a soldering gun ....a half pull on
trigger will heat it up fast (you will feel and hear the humm) - a full pull
will maintain the heat (no humm). |
|Keep a wet sponge, some soldering flux and good
quality 60/40 (0.063") diameter rosen-core soldering wire handy.|
|"tin" your soldering tip by heating, dipping in
flux, and touching with solder - this will help with heat transfer.
If your tip gets dirty ....clean with a wire brush and repeat above.
|heat from one side of the wire and add solder to the
other side (you want the "wire-heat" to melt the solder). You get a bad
"cold" joint if you don't follow this rule. |
|Minimize the amount of solder you use... too much
and it will get drawn back along the wire (under the sheath) and create a hard
sport that could break (and be difficult to detect).
|An excellent soldering source is
|If you every have the need to solder-splice 3 x 10ga
wires together you may have to resort to using two soldering guns to get
enough heat to suck the solder into the wires..... ask me how I know!!
2) Heat Shrink:
I started with a box of 4" assorted diameters of heat shrink
tubing from www.waytekwire.com. What I didn't realize is that there is a big
difference between "single wall non-adhesive" heat shrink and double
wall adhesive heat shrink. The double wall stuff is far
superior. I went out and bought a Milwaukee variable heat
gun for the job - what a great tool.
3) Delphi WeatherPak and MetriPack connectors:
Don't skip this step - these connectors will
protect all your exposed car wiring and provide a nice simple way to
disconnect components like headlights, horn, etc. Again you can buy from Waytek.
3) Circuit Testing:
Rather than risk flying something when testing
your harness..... buy a 12V Lantern battery. They are low amperage
but enough to test most devices.... even will make your horn chirp
Warning.... if you own a Optima Spiral Cell
battery ....and you have to charge for some reason (perhaps you left it on
a shelf for too long) never, never use a charger that supplies more than
12V-1amp supply. If you go higher you will fry the battery.
5) Dielectric Grease:
A little goes a long way. I have used it
everywhere there is an electrical connection that might corrode. All
the Connectors, ground posts, plug wires, etc.
6) License Plate Light:
While testing my headlights I would blow a
fuse when the headlights were on. After an hour of troubleshooting I
traced the problem back to my wiring of the license plate light.
Turns out that the two studs on the back of the housing are not intended for
a hot and ground wire. They are for mounting only. The hot
and ground must be connected inside the light. Should have
looked at this light a little more carefully before wiring.