Gauge lights intermittent on-off?
 

My gauge lights turn on / off on a 1 second on-off basis when driving. This is post-pnp install and turbo install.

Not sure where to begin?

Your wording is kind of weird. This only happens when moving? is it flickering or actually a timed on/off as if it's connected to a relay?

I would start with loose connections, obviously. Rule out the easy shit. From there I'd meter the harness at the cluster to see if the voltage is actually flickering or if it's isolated inside the cluster.

Honestly you probably just have a loose bulb.

Sorry about the wording. I don't believe this is a vibration issue or a connectivity issue. All of the gauge lights in the instrument panel turn on and off on a 1 second on, 1 second off basis. I will need to check if this is also the case when the car is off, but the ignition is on.

No problem - it just kinda made it sound like it only happens when moving, which would be interesting.

I would still start with the easy things, inspect the fuse for the cluster and re-seat it in the fusebox if it looks OK. Re-seat the connections behind the cluster.

If you're still seeing a timed on/off, you have something pretty odd going on. You'll definitely need a multimeter and wiring diagram to troubleshoot further. In this case I think it would be easiest to start testing at the cluster and work backwards on the circuit from there. All of the gauge illumination runs through the stalk switch, but I can't really see that causing this issue.