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© 2004 Directed Electronics, Inc. Vista, CA
This system is most commonly found in Ford, Mazda, Chrysler and GM vehicles. The door lock switch or door key
cylinder may contain either one or two resistors.
SSIIN
NG
GLLEE--R
REESSIISSTTO
OR
R TTY
YP
PEE:: If one resistor is used in the door lock switch/key cylinder, the wire will pulse (+)12V in
one direction and less than (+)12V when operated in the opposite direction.
TTW
WO
O--R
REESSIISSTTO
OR
R TTY
YP
PEE:: If two resistors are used in the factory door lock switch/key cylinder, the switch/key cylin-
der will read less than (+)12V in both directions.
D
DEETTEER
RM
MIIN
NIIN
NG
G TTH
HEE P
PR
RO
OP
PEER
R R
REESSIISSTTO
OR
R V
VA
ALLU
UEESS:: To determine the resistor values, the door lock switch/key cylinder
must be isolated from the factory door lock system. For testing, use a calibrated digital multimeter that is set to ohms.
IIM
MP
PO
OR
RTTA
AN
NTT:: To ensure an accurate resistance reading, do not touch the resistor or leads during
testing.
1. Cut the output wire from the door lock switch/key cylinder in half.
2. Test with the meter from the switch side of the cut door lock switch/key cylinder wire to a reliable constant
(+)12V source. Some good constant (+)12V references are the power input source to the door lock switch/key
cylinder, the ignition switch power wire, or the (+) terminal of the battery.
3. Operate the door lock switch/key cylinder in both directions to determine the resistor values. If the multi-
meter displays zero resistance in one direction, no resistor is needed for that direction.
4. Once the resistor value(s) is determined, refer to the wiring diagram for proper wiring.
ttyyppee GG:: ppoossiittiivvee ((++)) m
muullttiipplleexx
