VERY Strange - Alarm and central locking install.

[mike_nofx]

Hoping someone can explain whats going on with this alarm install! I have it all working, but its just too strange to be right.

First off its a Mongoose m20s alarm. And a generic central locking kit.

Both have been installed, and are working seperately, but not properly together.

Central locking kit has a brown and white wire coming from the module, these when earthed (seperately) lock and unlock the doors. This is tested, and works fine.

Alarm is installed, and it works fine other than the central locking connection. here is the central locking wiring.

1 Green - lock common
2 Blue - Unlock common
3 White - Lock NC
4 Brown - Unlock NC
5 Purple/orange - Lock NO
6 Orange - Unlock NO

Note that the orange wire is just a jumper wire connected directly to the purple wire socket.

When tested with a multi meter wires 1&3 and 2&4 have continuity.

Now heres where it gets weird. Connecting the brown and white wires from the c/lock module to either the green & blue or white & brown on the alarm does nothing.

After some experimentation we have managed to get a result. Connecting white to white and brown to brown from c/lock to alarm.
At this stage, the blue and green wires on alarm are both are showing 12v. (as do both the brown and white wires)

BUT if we earth both the blue and green wires the central locking and alarm all works fine!!!!

Heres how we have it wired up:

1 Green - Earth (before connecting to earth this wire shows 12v)
2 Blue - Earth (also shows 12v)
3 White - White on c/lock (shows 12v)
4 Brown - brown on c/lock (shows 12v)

As 1&2 and 2&4 have continuity, and 1&2 are earthed this means all wires now have continuity, all wires have continuity to earth, all wires show 12v when not earthed.

And central locking works. WTF is going on???????????

If anyone can understand what i just wrote, and can understand why the c/locking now works (and if its correct and safe!) has my respect!

Mike

[grubb]

this will give you a negative output on your alarm
white- no connection
green - lock
purple-earth this wire
orange- earth this wire
brown - no connection
blue - unlock