Battery is being drained

JMH_ELLISON

MEMBER
2001 LEXUS GS 430
4.1L
V8
2WD
AUTOMATIC
134,000 MILES

I got an electrical issue with my car that no one can seem to solve.

All I know of is that my radiator fan continues to run with the car off, draining the battery.

Late May I was told the fan motor was burnt out, so that was replaced along with the relays. Early June the car shut off again, and I was told the alternator had a bad diode, so the alternator was replaced along with new relays. The battery was said to still be good as of two weeks ago.

I did notice my coolant reservoir is very low when the car is cold, could that cause the fan to continue to run? The engine doesn't overheat or anything.

1 Reply

JACOBANDNICKOLAS

MECHANIC
109,885 POSTS

Welcome to 2CarPros.

The cooling fans shouldn't run continuously when the key is off. Something is supplying power to them all the time. To help me narrow things down, I need you to do something. First, there are three fan relays. They are all located in the relay box on the left side of the engine. See pictures 1 and 2. I need you to remove one relay at a time and then replace it until you hit a relay that turns the fans off. Let me know which one it is.

If you can, here is a link that explains how to test a relay. I will include a link that shows how to use basic testing equipment.

https://www.2carpros.com/articles/how-to-check-an-electrical-relay-and-wiring-control-circuit

https://www.2carpros.com/articles/how-to-use-a-test-light-circuit-tester

https://www.2carpros.com/articles/how-to-use-a-voltmeter

https://www.2carpros.com/articles/how-to-check-wiring

Let me know what you find or if you have other questions.

Joe

Images (Click to make bigger)