How-to-guides - Diode applications

Using a negative unlock and or lock output to arm or disarm a factory installed security systems

The diagram below shows how to use the (-) negative lock and unlock outputs to arm and disarm a vehicle’s factory installed (O.E.M.) security system. 

The diodes are needed to prevent the arm or disarm circuit from back feeding to the (-) negative pulse door lock activation wires to prevent the doors from locking or unlocking when the factory security system is armed or disarmed. 

The diodes will also prevent the lock and unlock circuits from back feeding to the factory arm and disarm circuit.  

Example: Sometimes an alarm, keyless entry, or remote start on some vehicles will interfere with the factory alarm and cause it to trigger. In those cases, the alarm or keyless entry must be interfaced into the factory disarm wire. 

This diode configuration can also be used to arm and/or disarm a vehicle’s factory security system when an alarm or keyless entry is used to lock and unlock the doors. Note: Some vehicle’s factory installed security systems arm passively only and will not have an O.E.M. arm wire in the vehicle.

Diode Isolate Multiple (-) Negative Door Triggers

The diagram above shows how to diode isolate multiple (-) negative door triggers to a single door trigger which can be used as the (-) negative door trigger to an alarm. 

The diodes are needed to prevent a back feed between the separate factory door triggers. 

Example:  This configuration can be used to isolate separate left and right door triggers found in many G.M. vehicles and can also be used to isolate separate front and rear door triggers found in some vehicles.

Diode Isolate Hood and Trunk Switches

The diagram below shows how to diode isolate the (-) negative hood and trunk triggers to a single trigger which can be used as the (-) negative instant trigger to an alarm. 

The diodes are needed to prevent a back feed between the hood pin and the factory trunk light circuit. 

This will prevent the factory trunk light from turning on when the hood is opened.

Diode Isolating the Starter Kill from Other Devices Using the Ground Output While Armed

The diagram below shows how to use the ground white armed output of an alarm to power other circuits other than the starter interrupt. 

The diodes are needed to prevent a back feed between the starter circuit in the vehicle and the other devices being powered.

Example:  This configuration can be used to power extra L.E.D.’s,   Scanning L.E.D.’s or other circuits needing a ground while armed.

Flash Separate Left and Right Parking Light Circuits with Flashing Light Output using Diodes to Isolate

The diagram below shows how to use the (+) positive flashing light output of an alarm or keyless entry to flash both the left and right flashing light circuits in vehicles equipped with separate isolated left and right parking light circuits.

The two diodes are needed to prevent a back feed between the separate factory parking light circuits. 

Note: The parking light circuits are usually high amperage circuits; therefore, diodes with an amperage rating of 6-10 amps must be used.

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