Sounds like one or the other is incorrectly wired...is the Viper system you have sensitive to voltage changes in the FJC ? If so, it's sensing the current draw of the PIAAs when you turn them on.I just install PIAA 520 FJ Driving Light Kit in my 07 FJ every time I put the PIAA light on my viper 5902 alarm starts to go crazy but when i turn off the PIAA 520 the viper alarm work fine what could be the problem
Does your Viper alarm activate even when the car is running ? It should be disabled, and unaffectd once you start the vehicle. If it only occurs when the car is off, you might have the power sources for both in a place that can't supply proper current to both. The PIAA relay power should be wired directly to the battery. Also check the relay trigger wire, which taps in the fuse box - make sure it isn't using a circuit that is powering the Viper system...