Hi guys,
I've got a 'H' reg (1990) 190E merc, and the central locking doesn't work. If you use the boot, it locks all of the 4 doors, but it won't lock the other doors if you use the driver or passenger door. Ideas??? Also, how does this system work. Going to the actuator thingy, there are 3 wires, a figured these to be live, earth and some sort of signal. What state should the signal wire be to lock the entire car??

Thanks for any info -Gavin