This is one of the most common type of door lock switch configurations
found in most vehicles. In most cases you will not need to add relays for
this type. Most of the newer alarms and keyless entries on the market today
have both positive and negative 200 ma door lock outputs that are usually
capable of activating the factory relays. Should you need to add relays
for a "3 wire negative" door lock system, just change both normally open
terminals (87) from 12V(+) to ground. If your alarm or keyless entry has
positive outputs only, you will have to connect the other side of the coils
to ground and connect your outputs as shown. The lock and unlock
wires below refer to the switch wires, not the motor legs.
4 Wire Reversal Door Locks
In this case, both motor legs of the door locks are normally
open. They neither rest at ground or 12v(+). The switch, when moved in
either direction, applies both power and ground directly to them without
the use of any relays.
5 Wire Alternating 12 Volts Positive Door Locks
Like the configuration above, the switch,
when moved in either direction, applies both power and ground directly
to motor legs without the use of any relays. Except, at the switch
in this case, both motor legs rest at ground . Therefore it is only necessary
to change the polarity of one motor leg to lock or unlock the vehicle.
Actuators / Reverse Polarity
This is practically identical to the 5 wire alternating 12V(+)
system above. The only difference is there's no switch!
Both motor legs rest at ground at the relays. To lock or unlock the vehicle,
polarity is changed on one motor leg.
Vacuum Type Door Locks
Found mostly on Mercedes Benz vehicles, the movement of the
door lock actuators is controlled by a central vacuum pump. The switch
changes polarity on a single wire that may rest at power or ground depending
on the state of the door locks. You can duplicate this with at least a
2 second pulse. If the alarm or keyless entry you are installing does not
have a 2 second or longer duration option for the door lock outputs, do
not use this diagram (it will not work unless you incorporate a timer into
Add Auto Lock without an Alarm or Keyless Entry System
You can easily add the convenience of auto lock to any vehicle
equipped with power locks without adding a keyless entry or alarm ( or
if the one you have does not have this feature). Please notice the relay
on the left. This is an inhibit to prevent the doors from locking the customer
out of his vehicle. When the key is turned to the "ignition on" position,
the doors will only lock automatically if the doors are closed. If the
vehicle has a positive door trigger, change terminal #85 of the left relay
to ground and connect the door trigger to #86 as shown. For auto unlock,
see next. For more info, click here.
Add Auto Unlock without an Alarm or Keyless Entry System
Like above, you can add auto unlock to any vehicle equipped
with power locks. Just connect the output of this circuit to the vehicle's
door lock circuit using the appropriate application.