Hi there

I have just spent two days transplanting my aftermarket alarm into my 2.5 V6.


Most of the connections were made in the main wiring loom although I made some connections at the central locking unit. These were for the lock and unlock pulses when arming and disarming the system, and for the door open signal when armed.

Before I fully refitted everything I tested the system and was pleased to have it working. The doors locked and unlocked on arm and disarm, and every sensor triggered the alarm when tested.

I fitted everything back and went for a drive. The first problem I noticed was that even though I have it set in the alarm, the doors do not lock on ignition (and would then unlock when turned off too). I am puzzled by this because as I mentioned, the doors do lock and unlock on arm and disarm, so I know I have got the wires right. That is, unless, I picked the wrong lock/unlock points. The points I chose are the same as those contacted when the key is manually turned in the door (these were the easiest connections to determine from the wiring diagram). A ground signal is supplied to the central locking unit when this happens and I therefore configured the alarm wiring to provide ground pulses for the locking rather than positive pulses I had on my old car.

I did look at directly connecting to the motor(s) but it seems these have their polarities reversed to lock or unlock. This is someting my alarm can not provide for.

So my first question is: are there any other connections I can use for either negative or positive trigger locking?



The second problem is that the ultrasonic sensors for the alarm I fitted always trigger when armed (but function correctly when testing). Could there be a conflict with the factory fitted ultrasonic sensors? I have the aftermarket sensors disabled for now so it's not a big issue but one I wouldn't mind fixing.

Because my alarm has extra stuff such as additional outputs, optional outputs, boot release, auto window close, secondary siren output.

Thanks; I wouldn't have done it otherwise but I like the options available from the four button alarm fob.