Are there any special relays or diodes needed to install door lock-unlock system on an afermarket car alarm?

Answer

It depends on the make and model of the alarm and what features you want. Some alarm systems have integrated relays for features like starter/ignition kill, and power door locks while others require external relays.

Relays are electrically actuated switches that handle large amounts of current. Alarms typically use relays to lock and unlock doors, switch current for starter and ignition systems on and off, and so on.

Diodes are basically one-way valves for electricity. They are used to insure that current travels in one direction. These are typically used in alarm installations to electrically isolate one sensor from another, preventing false alarms and other weird electrical gremlins.

As for whether you need relays and diodes for power door locks, here's a simple rule of thumb:

1. If the car already has power door locks, you can interface the alarm with the factory power locking system.

2. If the car does not have power locking, you will need to add the wiring, relays and actuators.

3. Diodes are not necessarily needed for power door locks, but it depends on the specific make and model of the alarm and the car.