Your Murano III is fine at night, but dead by morning. Here’s what a mechanic checks first — from fuse pulls to the smart key system — and whether you can keep driving.
If your Murano III waves a white flag every morning, the fault is usually not the battery or the alternator — it’s a slow electrical leak while the car is parked. A parasitic draw under 50 milliamps is normal; anything above that will drain a typical 70Ah battery in a day or two. Before you start throwing parts at it, understand that a draw like this is almost always a module refusing to sleep, a switch staying on, or an aftermarket device that never turns off.
The first suspect on the Murano is the Intelligent Key / Body Control Module system. When you lock the car, the BCM should go into sleep mode after roughly 10 minutes. If it stays awake — say a door switch is misaligned or the brake pedal switch is stuck — the CAN bus stays live and current keeps flowing. Another common hidden drain is the audio/navigation unit, which can keep drawing power if it fails to enter standby.
