HEATER/BLOWER MOTOR WIRE(S) (+12V in run position only)
Most vehicles will have (1) blower wire; however some Fords, newer GM vehicles and Chrysler 94 and up
will have (2) or more blower wires. To locate these wire(s) probe for wire(s) that only show +12V when
the ignition switch is in the RUN position only. This wire(s) will not show +12V when the ignition switch
is in any other position.
1.If your vehicle has only (1) blower wire connect the WHITE WITH BLACK STRIPE wire from the 4-relay
harness to this wire.
2.If your vehicle has (2) blower wires, connect the WHITE WITH BLACK STRIPE wire to both.
3.If your vehicle has (3) blower wires connect the unused WHITE wire from the 4-relay harness to the
third blower wire.
STARTER/CRANK WIRE (+12V only in the start position only)
The starter/crank wire is also in the main harness. Locate the wire that shows +12V only in the crank
position. This wire will not show +12V in any other position. Attach the YELLOW WITH BLACK STRIPE wire
from the 4-relay harness to this wire.
5
Note: Remove any paint below
the spade connector.
Factory Bolt
Spade Connector
Black Ground Wire
BRAKE INPUT
The brake wire is located on the switch near and above the brake pedal. The correct wire will show
+12V only when the brake is pressed. Connect the BLUE WITH BLACK STRIPE from the 18-pin harness to this
wire.
PARKING LIGHTS (+12V only with parking lights on)
Turn the parking lights to the ON position. (NOT YOUR HEADLAMPS).
Probe the wire(s) coming from your headlamp control switch. Find
a wire that will show +12V only when the parking lights are ON.
Connect the BROWN wire from the 18-pin harness to this wire. If
this wire tests as a (-) negative, see diagram.
DO NOT USE THE RED WIRE, TAPE OFF.
87a
To (-)Parking
Light Output
To Ground
Brown wire
from 18 pin
harness
To Ground
YELLOW
BLACK
WHITE
BLUE
RED
Optional part #775 required.
NEGATIVE PARKING LIGHT OUTPUT
FACTORY ALARM SHUT DOWN WIRE (FASD) (-)
If your vehicle is equipped with a factory alarm system (as most vehicles with a factory keyless entry
are) probe for a small gauge wire (usually found in the driver’s side kick panel) that shows (-) ground
when the door lock cylinder is turned to the unlock position using the key. This wire will usually show
a (+) positive voltage before turning the key. NOTE: Some factory disarm wires remain neutral before
you turn the key to unlock instead of +12v positive. Connect the RED WITH BLACK STRIPE wire from the
18-pin harness to this wire.
CHASSIS GROUND
Locate an easy to get to bolt or screw
located under the driver’s side of the dash and
attach the BLACK ground wire from the 18-pin
harness securely as pictured.
DIESEL INSTALLATION ONLY
Connecting the Glow Plug or Wait to Start Wire
When installing on a diesel engine, a wire that energizes the Glow Plug (also known as the Wait to Start
Wire), must be located and identified. This wire is usually located at the instrument cluster or at the ECM
(electronic control module). This wire will, depending on the year, make and model of the vehicle, test as
a (+) positive or a (-) negative.
TO TEST FOR NEGATIVE: Clip the test light to ground, then probe the wire and turn the ignition key on. The
“Wait to Start Light” on the dash should be illuminated, the test light should also be illuminated. When the
“Wait to Start Light” on the dash goes out and the test light also goes out this is a (-) negative wire.
Connect the GREEN WITH THE BLACK STRIPE wire from the 18-pin harness to this wire.
TO TEST FOR POSITIVE: Clip the test light to ground, then probe the wire and turn the ignition key on. The
“Wait to Start Light” on the dash should be illuminated, the test light should not be illuminated. When the
“Wait to Start Light” on the dash goes out but the test light is illuminated this is a (+) positive wire.
Connect the BROWN WITH THE BLACK STRIPE wire from the 18-pin harness to this wire.
NOTE: You will need to program your unit for Diesel Start Mode. See programming on page 11.
