Does this plug directly into the factory wiring?

Yes — the electrical connector is OEM-spec and connects to the factory harness without adapters or modification.

Will I need to drain coolant to install this?

Installation method varies depending on your vehicle configuration. Consult your service manual or have a tech confirm before starting work.

What's the return window if it doesn't fit?

Check the website return policy for specifics, but test-fit the assembly before running the engine to catch any clearance issues early.