oldglo

Hey guys, I have a 2005 RX330 and I think there is an electrical issue with it. If I don't drive it for 2 or 3 days, it completely kills the battery, to the point that it can't even be charged up. Im already on my third battery. What do you think could be the culprit here? And how to do I go about diagnosing it? Unfortunately, I don't know much about the car and why it started doing this as I just bought it.

Looking forward to hearing your response! Thanks in advance!

crj3545

If you are not handy, you will need a mechanic take a parasitic load measurement. The procedure from that point on takes some technical knowledge!

tawm

From my experience with a different car, there is an electrical short circuit somewhere. Maybe as easy as a trunk light left on; or as difficult as a short-circuited component which generates heat and slowly drains the battery. As the previous poster said, it can be difficult to trace where a short is, but a skillful sleuth with knowledge of the vehicle's electrical system could do it.

NVAKeith

iTrader: (1)

Here's another owners experience:

https://www.clublexus.com/forums/rx-2nd-gen-2004-2009/856271-battery-eating-2006-rx330-finally-solved.html

oldglo

Thanks everyone for the responses. I did a parasitic draining check on my car (pulling fuse while multimeter was plugged in). And, I noticed that there was a 500mA draw. When I removed the ECU-B fuse, it went down to <15mA (normal). Anyone have any experience with this fuse? It seems that I definitely won the lottery in regards to how many components this fuse controls. I have attached a picture from the manual, not sure what I need to do next to test out the components individually. Any advice?

Thanks!

rx330 owners manual. ECU-B Fuse

NVAKeith

iTrader: (1)

I searched for ecu-b and found this:

https://www.clublexus.com/forums/rx-2nd-gen-2004-2009/785954-current-drain-of-850ma-at-battery-remove-26-ecu-b0-and-68-power-goes-to-0-a.html

interesting note about the ecu taking time to "fall asleep" to get an accurate draw reading

HtownBlue

Don't test that draw on that fuse for 10-15 minutes after shutting off Car.
Next, your draw is likely coming from something controlled by the ECU B if it is still under load after a resting draw test.

If if you don't know much about cars, your skill set is unlikely to lead to a solution friend. I would absolutely read more and take it to a trusted mechanic.