2011 Sonata aftermarket fog lights

Installed some customer-supplied WARN wireless fog lamps on a customer's car. Immediately after installation, the controller failed and would not continue to activate the relay controlling the fog lamps. (I verified the location of the failure by testing the system).

Call to WARN resulted in a recommendation to uninstall the entire system and reinstall another one (which would have resulted in a significant labor charge to the customer). Eventually got them to send just the component I needed, only to have it do the same exact thing.

Again called WARN, who said that I'd need to replace the whole system. (Why, so I can charge the customer big money to have the same thing happen a third time?)

Ultimately, I directly wired the relay to the low beam signal, bypassing the controller, and miraculously the fog lamps illuminated whenever the low beams were on.

My assessment on this system: Fog lamps okay. Control module junk.

My dear Hyundaitech,

Have we entered an age in which "accessories" are no longer controlled by regular switches via wires, or are we dealing with a single universal power feed to all components, which are remote switched by switching modules that are activated by signals in a universal data stream throughout the vehicle? This sort of system would require both complex "smart switches" as well as "smart" local controllers at each device.

If it's data, in your opinion, are we now in an awful knotty territory in which data can buffet between incompatible systems, causing components to mysteriously fail for no reason?

I gotta hear this from your mouth, er, fingers.

Richard