Wiring Information for Owners
Taillight Wiring
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The tailights on 1968s are very unique.
Here's some basic information on factory installation of tailights.
The
tailight wiring harness (runs down left rocker) is a standard Mustang part. The
bulb sockets have been removed. This leaves three wires on each side of the car.
These three wires are spliced into the "dynamite" sticks.
Original
dynamite sticks are inside a cardboard tube and have a large plug on the end.
The plug is really the key. It connects the tailight wiring to the bulb harnesses.
I sell some very nice reproductions of the sticks and the harnesses.
This diagram shows the proper splicing locations. The factory used
three connectors on each side of the car. Sometimes as many as six connectors
were used on each side.
The most common reason for light failures are
poor grounds and connections. You must also insure you are using a #323 flasher
assembly under the dash. The more common #552 will not work in most cases.
Underdash Tilt Mechanism
The 1968 tilt bracket is unique to 1968
cars. Most components on the bracket are interchangable with other systems. Only
a few cars, built at the beginning of production, do not have the tilt steering
option.
The tilt steering system is fussy on a good day. In order for
the system to work, you must have vacuum, electrical and mechanical components
working together. It is comprised of three parts under the dash.
These
parts are the tilt solenoid, the vacuum motor and the relay. Remove the wiring and the mechanism to perform the testing.
The tilt
solenoid is interchangable with some other years. It can be tested by grounding
the solenoid to bare metal. Next, touch a 12v wire (from pos battery) to the
brass spade and release. You should hear one "click"
The relay can be
tested in a similar fashion. Ground the relay and touch a 12v pos wire to the
terminal marked "1". Release the wire. You should hear one "click". The relay is
also interchangable.
The vacuum motor is made from black plastic. White
cannisters are from other years. Inside the cannister is a small switch. If this
switch is bad, the car will not start. This is a common place to bypass the tilt
mechanism. By attaching a looping wire, the switch can be bypassed. Often times,
previous owners, cut these wires for this reason. The switch must be closed to start the vehicle (plunger on cannister pulled out).
Tilt wiring harnesses
are now available and I do sell them.
Oil pressure Wiring Installation
There are several variations of the 1968 oil pressure wiring.
I have not seen the first version, but it runs down the left side of the engine bay with the windshield
washer hoses and then over to the sender. It is possible this was not used in production.
Some GT350s have a wire that uses an eyelet on the end. Some have a elbow connector. The GT350 harness does not normally get spliced
as shown below, but later cars may have been spliced?
For all GT500s and GT500KRs the following installation should be correct. I have seen elbow and eyelet connectors on the ends.
If you need an elbow connector, you can use the portion cut from your intake wiring. That is the way the factory did the modification.
Simply cut off the attached eyelet and discard it.
The picture above shows the Ford intake wiring harness. It is base part number 14289. It has three leads
on the top of the intake. The white/red goes to the oil pressure sender. This wire is attached to the "idiot" light in
the dashboard. The red/green wire is for the distributor (not connected in photo). The red/white wire is for the temperature sender.
The scissors shows where the oil pressure wire was cut by AO Smith. This wire is now dead and the dash light
becomes non-functional. AO Smith left the dead wire in the harness.
The cut end of the wire (attached to the oil pressure sender) is then spliced to the single,oil pressure
wire running out the firewall from under the dash. A white Scotch-lok connector was used.
The single white/red wire is the wiring from the back of the Shelby console oil gauge. It normally lays on the intake or is installed
under the rubber j-hooks.
Reproduction Wiring Harness Check
If you have purchased either a reproduction main harness or a left hand rocker (tail light feed) wiring harness
please check the following wires:
On some harnesses, the two colored wires shown in the photo may have been installed into the plastic plug incorrectly. This is easy to
correct. This is the left hand rocker wiring harness. The end shown is near the driver's side kick panel when installed in the car.
Inspect the main harness and the tail light harness to make sure the wire colors match when plugged together.
If the wires do not match, remove the wires from the plug and re-install them correctly.
It's best to use a tool like the one shown. Insert the tool in the end of the plug to
depress the barb on the wiring. Gently, pull the wire from the back. Re-install the wires.
Old Plugs vs. New Plugs
In a few cases, I have run across new wiring plugs that will not plug into old wiring plugs. If you are mixing old and new harnesses, please be aware of this fact. The molded plugs DO NOT seem to be an issue. This only relates to the plugs with pin connectors.
If you run into this problem contact me and we will come up with a solution.
Ignition Switch problem discovered. After contacting the manufacturer, this is what I have come up with:
Some new ignition switches are not compatible with the old style ignition plug in the main harness. I will be making the necessary modifications to any harnesses shipped after 10/19/09.
This picture shows the original plug sitting over the new reproduction plug. You can see the shape is slightly different (circled area). Failure to address this variation in the plug size can cause damage to your ignition switch. [Note: You do not have to worry about the notch in the side of the plug]
This photo shows the location that needs to be filed down approximately 3/32 of an inch.
REPRODUCTION WIRING WARNING
Please do not cut your new wiring. If you need help plugging things together or need to know the specific functions of certain plugs, I will try to help.
If you need more help, please email me. Please help keep this page "private"
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