Will this plug directly into the factory wiring?

Yes. This mirror uses OEM electrical connectors that match the factory harness on these Siennas — no splicing or adapter needed.

Does the heating function work independently from the power adjustment?

The heat element activates separately through the factory control switch. Both power and heat are integrated into the same assembly.

What's the return window if the mirror doesn't function as expected?

Check your purchase confirmation email for the return period tied to your order. Most electrical returns require a 30-day window from delivery — test functionality before the deadline.