Hi there, I have a problem with my 2009 Lexus RX350. It has been having a battery drain for a year I have changed the battery around three times, and the alternator seems to be normal. Somehow, the battery drain happens during the cold weather only. Also, the previous owner has changed the headlights to an aftermarket, which the AFS light is on, and I have noticed that some plugs are disconnected from the aftermarket headlights. My guess is that the vehicle has a parasitic draw, but I am not exactly sure where it would come from. Also, all of the memory seats, lights, and windows are working properly. Somehow, my son has an IS350, and it has been working properly and starts up every time in negative temperature, but not my RX350 lol. My question is that where do you think the draw could come from. Any advice would be appreciated. Thank you so much. *ps the RX350 has a navigation screen*

 

Also, relating to my first thread about my RX350 battery drain, does anyone know what this ground connector for. I saw that an anti-corrosion for battery is installed on the car, but I don't know if it is connected to it or not. I don't even know if it works or not lol.

 

I'd start at those aftermarket headlights.....Thats a bummer that the po went cheap & your paying for it.
Welcome to CL btw......I'd also check your oil cooler lines to see if the oem spiced rubber hoses have been replaced as well as the bank one vvt rubber spiced hose has been replaced as well.

 

Get an Amp meter. After you shat off the engine put it in the positive cable from the battery. Posted wat you got EXACTLY. Good luck.

 

Hi there, thank you for the comment. After turning off the engine right away, my battery is about 12.3-12.4. Usually, after an hour or two, it drops to about 12.1-12.2. I will definitely check again and give the exact number. Thanks again

 

Hi there, thank you for the advices and thank you for the welcome. I am also guessing it is probably the aftermarket headlights too. I saw that there are missing plugs that don't connect to the aftermarket headlights. The previous owner said that he replaced it because the cables or connection of the OEM headlights rusted and broke, so a mechanic replaced both. Would you think that I should purchase OEM ones from marketplace or the junkyard, and is it the worth it? So far, my RX350 is around 210,000 miles and the only problem it has is a seal leak in both differentials. Thanks again

 

How long you have the car? After you of you have the minimum12.6 - 12.8 V. Wat I ask for is AMPS. But if I would you, I change the battery. Having a battery drain is normal. Having too much is a problem. The old battery doesn't hold the charge. Check sees wat year the battery was made. Good luck.

 

>>>>As the OP mentioned, he's changed out the battery muliple times.......

 

I will definitely check out the AMPS soon. I have the car for about 10 years or so. The problem started for a year. The newest battery changed is 2025. My guess is the previous owner's aftermarket headlights. The wiring looks untrusted and it looks like he has not took good care of it at all lol.

 

It is not connected to anything. Remove it. Otherwise one day it will get you in trouble.

 

That is not factory so no one can tell you what it is for except the person who instlaled it... looks like it goes to nowhere though. OEM would not have an "inline" fuse holder like that

 

Turn ON the engine and make voltage check on the battery.

 

Please.confirm, you replaced the battery 3 times with a NEW battery?

This is important.

Also, what brand of battery?
Also, did you replace all 3 batteries with the same brand under a battery warranty program?

Details please. 😀

 

Hi, the battery was replaced 3 times with new battery every time. The battery is from Kirkland Costco, and it was replaced under a battery warranty program. My son's IS350 has the same battery brand it lasted about eight years so far.

 

Hi, thank you for details.
I have to ask because walmart batteries are trash and sometimes people replace with used batteries too.

Ok cool, not using walmart battery. Lol

Parasitic drains can be difficult so I like to start with basics first before going there.

What is the charging voltage when the engine is running, measured at your battery posts?

Do you have good clean battery connections?