Not sure if this should go here or under the electrical section, so feel free to move.

I'm in the process of installing a Viper alarm in my '13 F250 Lariat. Everything is hooked up and working except for the tie in for the door pin. The instructions tell me its the Green/Violet wire in the driver's door kick panel harness, or alternatively I can tie it into the same wire at the BCM in the passenger kick panel. Well, i'd prefer to keep it on the driver's side (along with all the other connections...), but in the harness there are no less than 5 Green/Violet wires. Any idea on how to determine which one?

 

A test light is all I ever use to verify correct wires.

For a 2013 you could have picked up a Ford alarm kit and had it installed in your driveway in about 5 minutes. I don't think many people know it is an option that is available for all 2011+ F-150's and Super Duty's. No wire splicing needed. Pick up an optional LED light for another few bucks to complete the package.

 

says 2012 but should be the same for 2013

2012 Ford F350 Auto Alarm Wiring Instructions

Battery Constant 12v+ Positive Wire (+): Blue/Red
Battery Constant 12v+ Positive Wire Location: Ignition Switch Harness

Starter Positive Wire (+): Blue/White
Starter Positive Wire Location: Ignition Switch Harness

Second Starter Positive Wire (+): N/A
Second Starter Positive Wire Location: N/A

Ignition Positive Wire (+): White/Orange
Ignition Positive Wire Location: Ignition Switch Harness

Second Ignition Positive Wire (+): N/A
Second Ignition Positive Wire Location: N/A

Third Ignition Positive Wire (+): N/A
Third Ignition Positive Wire Location: N/A

Accessory Positive Wire (+): Brown/Yellow
Accessory Positive Wire Location: Ignition Switch Harness

Second Accessory Positive Wire (+): Violet/Green
Second Accessory Positive Wire Location: Ignition Switch Harness

Key Sense Wire: Blue/Gray
Key Sense Wire Location: Ignition Switch Harness

Parking Light Negative Wire (-): N/A
Parking Light Negative Wire Location: N/A

Parking Light Positive Wire (+): Violet/White
Parking Light Positive Wire Location: At Smart Junction Box

Power Door Lock Negative Wire (-): Blue/Green
Power Door Lock Negative Wire Location: In Harness in Driver Kick Panel

Power Door Unlock Negative Wire (-): Yellow/Violet
Power Door Unlock Negative Wire Location: In Harness in Driver Kick Panel

Door Trigger Negative Wire (-): Yellow/Gray
Door Trigger Negative Wire Location: At Smart Junction Box

Dome Light Supervision Wire (-): Green/Blue
Dome Light Supervision Wire Location: At Vehicle Headlight Switch

Trunk Trigger Negative Wire (-): N/A
Trunk Trigger Negative Wire Location: N/A

Trunk Release Negative Wire (-): N/A
Trunk Release Negative Wire Location: N/A

Sliding Power Door Wire: N/A
Sliding Power Door Wire Location: N/A

Horn Negative Wire (-): Yellow/Red
Horn Negative Wire Location: In Harness at Steering Column

Tachometer Wire Negative Wire (-): Blue/White
Tachometer Wire Negative Wire Location: At PCM Module

Wait To Start Wire: N/A
Wait To Start Location: N/A

Brake Light Positive Wire (+): Violet/White
Brake Light Positive Wire Location: At Switch Above the Brake Pedal

Factory Alarm Arm Wire (-): N/A
Factory Alarm Arm Wire Location: N/A

Factory Alarm Disarm Wire (-): N/A
Factory Alarm Disarm Wire Location: N/A

Factory Anti-Theft System: Ford PATS or Securilock Vehicle Key Immobilizer
Factory Anti-Theft System Location: Key Sends RF Signal to the BCM Module