adding remote locking

[Marc Swanson]

> Hey, would it be possible to add this to a Coupe GT? It has vacuum actuated
> central (power) locks. When you unlock one door either with the key or by
> pulling up the knob, the other one unlocks too. Any thoughts? Sure would be
> nice...


It seemed easy to me at first, just hook up the positve trigger wires for
lock and unlock from the keyless entry system to the wires running from the
drivers door actuator to the pump in the trunk.. but it gets trickier than
that.

The way the actuator in the door works is to always have one of the two poles
connected to the common 12 volt supply.  The pump itself is responsible for
knowing when to stop running the motor by monitoring the pressure on the
vacuum line.

In order to make it work like I wanted it to (be able to unlock/lock the
doors with the key OR remote control) I had to build some logic into the
circuit.


I plan on writing up a quick and dirty page describing this in detail, but
basically I used two SPDT relays with two diodes to make it so that whenever
EITHER the lock or unlock button on the key fob is pressed, the relays break
the connection between the door actuator and the pump and switch the
connection on the pump side to the outputs on the remote locking unit.  This
way, when the transitter is done sending the lock or unlock pulse, the relays
close back down and the NC contacts return the connection between the
actuator and the pump which has by now already switched states from unlocked
to locked or vise-versa and the +12 volts will be on the opposite wire as it
would be if the key was turned.

Hard to explain but once i upload a .jpg it should be pretty clear.

The other way to do it would be to add a motor in the drivers door that pulls
down on the actuator rod when locking the doors or pushes up to unlock.  This
has the advantage of not needing any special wiring but it seemed silly to me
to add another motor into the door when one wasn't _really_ needed.




HTH


-Marc-
87 4ktq
88 90q