This 2019 Airstream Atlas had a failed Firefly Multiplex G7A controller, and it was causing some seriously strange behavior.

As soon as power was switched on, the heating and air conditioning systems would start turning on by themselves — everything! The AC, furnace, and other systems were acting like they had a mind of their own. Wild.

It was time to replace the failed G7A controller.

Watch as I replace the Firefly controller and get the multiplex system back under control. This procedure can also be helpful when replacing other Firefly G-series controllers in RVs.

If you’re troubleshooting a Firefly Multiplex system, G7A controller, RV AC or furnace turning on by itself, or other strange electrical behavior, this is one you may want to watch.

We believe that the failure was caused from 240V to the 120V system.