Table of Contents
Advertisement
3 Wire Positive Systems:
system as the 3 Wire Negative, except the vehicle's doorlock switches use 12
volt positive pulses to operate the vehicle's doorlock relays or control unit.
Examine the wires on the back of the switch. Of the three wires:
-
One wire is Constant Positive 12 Volts.
-
One wire will show Positive 12 Volts when the switch is pushed to "lock".
-
One wire will show Positive 12 Volts when the switch is pushed to
"unlock".
With the switch at "rest" (not being operated), these two wires will read
Ground, but unlike the following 5 Wire Reversal system, this Ground is not
a full, or "chassis" Ground. A Digital Multimeter (DMM) can be used to test
this. Set the meter for "ohms", and put one meter lead on the target doorlock
wire and the other to Chassis Ground. A 5 Wire Reversal system will read very
close to "zero ohms", which indicates that the target wire is resting at Chassis
Ground. If the target wire is indeed a 3 Wire Positive "switch" wire, the reading
will indicate Ground which is present through the vehicle's relay coil, which
typically produces a reading of approximately 150 ohms. As in a 3 Wire
Negative system, the wires from the switches operate doorlock relays or a
doorlock control unit with built-in relays, and the correct connection point
is between the switches and the relays.
Diagram Of A Typical 3 Wire
Positive Doorlocking System
Doorlock Switch
"Unlock" wire
"Lock" wire
Interface performed
within in this area
Page - 21
A 3 Wire Positive is the same basic
Doorlock
Actuators
Vehicle's Doorlock
Relay Control Unit
Unlock
Lock
+
+
Hide quick links:
Advertisement
Table of Contents
