12 © 1999 Directed Electronics, Inc. Vista, CA
harness 2 (H2), (+/-) door lock outputs
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door lock wiring diagrams
This system can control two common power door lock types without any additional parts! To interface with some
vehicles or if an actuator is to be installed, you will need a 451M Door Lock Relay Satellite or two relays.
This security system can control Type A door locks directly, with no additional parts. The switch will have three
wires on it, and one will test (+)12V constantly. The others will alternately pulse (+)12V when the switch is
pressed to the lock or unlock position.
If you cannot get to the switch, and you find a set of wires that pulse (+)12V alternately on lock and unlock,
you must take care to ensure that it is not a Type C direct-wire system.
IMPORTANT! If you mistake a Type C direct-wired system for a Type A positive-pulse system, the
module will be damaged!
Here is a test: Cut the wire which pulses (+)12V on lock, and then operate the switch to unlock.
■ If all doors unlock, the vehicle uses a Type A system.
■ If you lose all door lock operation in both directions, you are operating the master switch in a Type C system.
■ If one or more, but not all, motors stop operating, you have cut a wire leading directly to one or more motors.
Reconnect the wire and look for another wire.
Many domestically-made GM vehicles use Type A locks. However, many more GM vehicles are Type C than in pre-
vious years. The full-size pickups (1989-later), many of the S10 Blazers, the Corvette, '95 Cavalier/Sunfire 1993
and newer, Camaro/Firebird all use Type C door locks, and cannot be controlled without a 451M! Almost all domes-
tically-built Fords are Type C. Ford builds almost no Type A systems. Chrysler builds both Type A and Type C, so
test carefully.
type A: (+) 12V pulses from the switch to the factory relays
BLUE (-) UNLOCK, (+) LOCK OUTPUT
EMPTY UNLESS USING 451M
GREEN (-) LOCK, (+) UNLOCK OUTPUT
H2/A
H2/B
H2/C