Q: GL450 has no power. It’s completely dead.

It’s possible the battery might just be coincidentally dead. So, to rule that in or out, the first thing to do is load test the battery. If the battery is fully charged, then an electrical system diagnostic must be performed. The carpet cleaning might be related to the outage and you will know for sure once a diagnostic is performed. The situation is not as dire as you might think though. A worse circumstance (much worse) would exist if you were writing in stating, "sometimes there’s full power, sometimes there isn’t". A global electrical failure of the type you’re describing will often have one big obvious (non-intermittent) cause (or limited causes) in one spot. Basically, with regard to any of those circuits you refer to, you just do a circuit trace. At some "early" (close to the battery electrically speaking) point there is likely to a major fault (interruption) in the circuit. That could be a fuse, fusible link, ground connection, circuit opening relay, power center component, and so forth. The fault may be common to all of the circuits that are out but certainly will pertain to at least a few. If you want a prompt resolution of this, right at your location, please request an electrical system diagnostic. If you request that service, the responding certified mechanic will get this diagnosed and resolved, right at your location. If you have further questions or concerns, do not hesitate to re-contact YourMechanic because we want you to make the most of your repair dollars and help you to get the best possible results.