I've tried all methods I can find so far, and none have worked. Here's the deal:

2000 RX300. Battery has drained more than once (family member's second car). The keyless entry does't work, nor do the power locks when the truck is off. When the truck is running, the door locks work just fine.

I'm at my wits end. Help?

*edit - yes, the batteries are fine. The keyless and interior locks used to work.

 

Some Questions: How do you know the car battery is fine? Do you have a voltmeter? Can you measure battery current drain (im milliamps)? Is there significant corrosion on/near the battery terminals (including under the red cover)?

The key is that the locks work when the engine is running. That is good news. My first guess would be battery terminal corrosion. Grounding problems are also a possibility. A slipping fanbelt that reduces battery charging comes to mind too. But, these are just guesses without voltmeter readings.

 

Hi Bob,

How do you know the car battery is fine? - The battery has been tested.

Do you have a voltmeter? Can you measure battery current drain (im milliamps)? Is there significant corrosion on/near the battery terminals (including under the red cover)? - The entire charging system was checked over at Lexus yesterday. We didn't notice the issue until well after we left the dealer.