Right this is a post mainly to help out Napster but other people might find it helpful too.
on the nissan factory central locking, you have 4 wires going to the door motors (this is on the later models with the more advanced central locking, i belive it is post 96)
there are two thick wires and two thin wires,
one of the thin wires is black, which is ground, the other wire is red and yellow. this is the signal wire.
if you pull the plug out of the central locking box which has the two red and yellow wires going into it (one for each door) then the central locking should either lock or unlock, i cant remeber what it does but i think it locks.
if it locks, then that means when the signal wire is cut it will lock the doors. this is because when the locks work they either connect or disconnect the signal wire from ground, and by cutting the wire you are disconnecting it from ground which simulates the lock being locked.
obviously for the other way round you must ground the wire to unlock the locks,
to do this you need a negative pulse from your central locking box, attach this pulse to the yellow and red wire. this way when you push the button on the remote, it will send a negative signal to the control box which will unlock all the locks.
the next bit is a bit more tricky, you need a relay with a normally closed option. wire the yellow and red signal wire so that it goes through the normally closed relay. that way the wire is intact and is still connected to the locking motor in the door, but you can cut the wire by activating the relay. then all you have to do is operate the relay with the remote, either with a constant ground and a positive pulse, or a constant positive and a negative pulse. which ever is easiest.
see the attached diagram.
let me know if you have any more problems
on the nissan factory central locking, you have 4 wires going to the door motors (this is on the later models with the more advanced central locking, i belive it is post 96)
there are two thick wires and two thin wires,
one of the thin wires is black, which is ground, the other wire is red and yellow. this is the signal wire.
if you pull the plug out of the central locking box which has the two red and yellow wires going into it (one for each door) then the central locking should either lock or unlock, i cant remeber what it does but i think it locks.
if it locks, then that means when the signal wire is cut it will lock the doors. this is because when the locks work they either connect or disconnect the signal wire from ground, and by cutting the wire you are disconnecting it from ground which simulates the lock being locked.
obviously for the other way round you must ground the wire to unlock the locks,
to do this you need a negative pulse from your central locking box, attach this pulse to the yellow and red wire. this way when you push the button on the remote, it will send a negative signal to the control box which will unlock all the locks.
the next bit is a bit more tricky, you need a relay with a normally closed option. wire the yellow and red signal wire so that it goes through the normally closed relay. that way the wire is intact and is still connected to the locking motor in the door, but you can cut the wire by activating the relay. then all you have to do is operate the relay with the remote, either with a constant ground and a positive pulse, or a constant positive and a negative pulse. which ever is easiest.
see the attached diagram.
let me know if you have any more problems