* Faulty power mirror motor(s): A malfunctioning motor can draw significantly more current than normal. This is a common culprit. The motor may be seizing, shorting, or have a worn-out gear.
* Wiring issues: A short circuit in the wiring harness for the power mirrors can cause a large current draw. This could be a frayed wire, a pinched wire, or a connection issue.
* Power mirror switch problem: A faulty switch might be stuck in the "on" position or internally shorted, leading to excessive current flow.
* Overburdened electrical system: While less likely to only affect the mirrors, a general problem with the vehicle's charging system (alternator, battery) could make even small current demands more noticeable on the gauge. If other electrical components are also acting strangely, this is a more likely cause.
* Loose or corroded connections: Poor connections at the battery terminals, fuse box, or in the mirror wiring can lead to increased resistance and higher current draw.
In essence, the battery gauge is reacting to a substantially higher-than-normal current being pulled from the battery when the power mirrors are activated. This isn't normal behavior and points to a fault within the mirror system or related electrical components. You should have the vehicle checked by a mechanic to diagnose and fix the problem before it causes more significant damage or leaves you stranded.
