1995 landrover discovery no ecu

My factory alarm/remote lock ecu recently died. The alarm would still work, but the power locks would not. Since the ecu is expensive, I have decided to install an aftermarket system. However, prior to installing the aftermarket system, I would like to get the power locks to work. This is what I have. The ECU has been removed. I have two wires coming from the lock actuators (Orange and Pink), and one wire from the key switch (unlock is grounded, lock is open). For the lock actuators, If I momentarily apply 12V to the O wire and ground to the K wire, the locks will lock. When I apply 12V to K and ground to O, the locks unlock. I believe that I will have to use a two relay system that will provide the proper momentary polarities for the O and K wires. Can anyone provide a circuit drawing that would make things easier. Also, does it matter if the lock actuators have continuous voltage applied. Thanks, Denis

Pink and Orange are the motor wires, you would need an alarm with built in relays, lock and unlock normally closed go to ground, lock and unlock common, use a 12v+ perm with a 20 amp fuse, normally open (lock side to Pink) and normally open unlock to Orange.

Howie,    Thanks for the reply. I realize that I should get an alarm with built-in lock relays, but does it matter if the relays provide constant power when locked/unlocked. Or do these systems have momentary type relays. For now, I just want to get the central locks working so that I can lock/unlock all doors from the driver door lock. I'm also a little confused with your comment "normally open (lock side to Pink) and normally open unlock to Orange". How does this take care of the revesrs polarity/ground issue. Also, does it matter if 12V is constant at the actuators, whether open or closed. Thanks, Denis

Read the sections on relays and locks.Certified Security Specialist

Always check info with a digital multimeter.

I promise to be good.

Tell Darwin I sent you.

I've been sick lately, sorry I won't be on much.

How will you control the relays without an alarm or a means of triggering the relays. Unless you have 1 wire going to either live or ground on turning key in driver's door you will have no way of triggering the relays, hence the advice to use an alarm.

For now, I should be able to control the relays using the key switch wire. When I turn the key to unlock, I will get a ground from the yel/pnk wire that previously went to the alarm. It gives a ground when the key is turned to unlock, or when the lock button is pulled up. It is open with the key set to lock, or the lock button pushed down. As for reading the section on relays and locks, I did just that. I couldn't find any info on keeping 12V applied to the lock actuators. Denis