Wire Reversal Rest At Ground Systems - Crime Guard 328i2 Installation Manual

5 Wire Reversal Rest At Ground Systems

This power doorlock system differs from the negative and positive pulse
systems in that there is no doorlock control unit or relays. In this type of system,
the switches themselves supply the positive voltage directly to the doorlock
actuators, and, more importantly, provide the return ground path. It is impor-
tant to note that the lock & unlock wires in this system actually rest at chassis
ground. This means that both the lock & unlock wires must be "opened", or cut,
to make the proper connections.
Examine the wires on the back of the switch. (Normally 5 wires will be found)
1) One wire will show (+)12 volts, regardless of the switch's position.
2) Two wires will be grounded regardless of the switch's position.
3) One wire will show (+)12 volts only when the switch is pushed to "lock".
4) One wire will show (+)12 volts only when the switch is pushed to "unlock".
-When the vehicle's lock & unlock wires are found, they must be cut (one wire
at a time). If the correct wires are cut the door lock system should not operate
from the primary switch.
-Notice in the diagram that the driver's switch is the primary or "master" switch.
The half of the cut wires which come from this primary switch are referred to
as the "switch" side. The half of the cut wires which go to the secondary switch
are referred to as the "motor" side. Even though the cut is made between the
switches, the two sides are still correctly called the "switch" and the "motor"
sides.
Warning: The 5-wire Reversal rest at ground system can be easily confused
with the Positive pulse system. This is due to the fact that both systems
show (+)12 volt pulses on the "Lock" & "Unlock" wires when the vehicle's
switch is pressed respectively. It is critical to correctly identify which type
of system is present in order to avoid damage to the vehicle and the unit.
3 main differences between a Positive pulse and a Reversal system:
1) In a Reversal system the Lock & Unlock wires rest at a solid ground,
while in a Positive pulse system the Lock & Unlock wires show partial
ground.
2) The switch in a Reversal system will have 5 wires, while the switch in a
Positive pulse system will have 3 wires.
3) A Reversal system has no factory relays or control unit, a Positive pulse
system does.
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