maorsela

Hi everyone,

my 2002 started draining battery about a week ago.

I noticed my interior dome light was always on when in 'DOOR' position, so I turned it off. The battery still drains.

I started digging in the fuse box and using a multimeter I found out that there are 2 fuses that cause a drain:
Disconnected battery negative and connected the multimeter between the negative battery and negative cable.
1. DOME (10A) - draws about 1A, all doors are closed, no dome lights are on, no instrument panel indicators, nothing
2. ECU-B (7.5A) - draws about 0.3A

I removed these 2 fuses and am able to drive the car, info screen in console is completely off but A/C still works.

Any idea what can cause the drain and what is ECU-B responsible for?

Can anyone recommend a car electrician in Tucson? or is the Toyota dealer my best bet?

Thanks!

salimshah

Do you have any accessory plugged into the the cig-lighter? Any after market stuff like Amp/remote_starter etc?

Why not Lexus dealer? They may have the highest /hr rate but they may have the best knowledge and can trouble shoot faster. It might be cheaper to go then. Key word being "might".

Salim

maorsela

Thanks Salim.

I only have a phone charger plugged into the cig lighter. Nothing changed in years... Only after market I have is the BT adapter sitting behind the radio inside the console.

I will start taking things apart and see if I go anywhere.

I might stop by the Lexus dealer and see what they say, thanks!

salimshah

My money is on one one of the add on or in its wiring. Lexus would most likely ask all add on things to be removed or they will remove them and charge you labor time.

Salim

fastnoypi

what was the last maintenance done or thing that you took apart and reinstalled? Sometimes wires get pinched unknowingly on the re-install and could ground out.

Anyways, i reached out to my friend in Tuscon. The auto electrician he had good experience with was Regis Auto electric in Tuscon...however it was on his Subaru. You may try to reach out to the shop and discuss their expertise with Toyota/Lexus. My Lexus owner friends in AZ go to Lexus of Superstition Springs and Lexus of Chandler which may be too far a drive..but again that is for regular maintenance, not auto electric troubleshooting. Personally, i've never had luck with dealerships troubleshooting auto electric in all the cars i've owned..but have had quick turnaround and diagnostics from these independent auto electric shops that do it all day.

Lexmus

maorsela,
This relatively recent thread has an issue sounds suspiciously like yours:
https://www.clublexus.com/forums/rx-...g-battery.html

He says the two circuits DOME and ECU-B are high initially, but drop down close to zero after 20 minutes. But he still gets a drained battery after a week or so. No solution was posted, but maybe those two circuits are not the actual issue in your case. I would post on that thread and see if the OP there might report back with an update to share.

Bill Dowd

This only a shot in the dark but you could possible have a bad cell draining the batter.
This happened to me on a new battery a while back just a thought.

maorsela

Called Regis, they won't touch the RX

But they gave me a recommendation, Borst Automotive, and the lady said they do Lexus' all the time, so going to give them a shot. I too hate the stealership, I rather give a local small biz a chance.

I haven't done anything to the car in years, last big thing that was done was the timing belt and water pump 3 years ago @ 120k, I also installed HID headlights 4-5 years ago, the rest is oil changes. I always had issues with the interior dome lights, the rear door doesn't work well and the one in the middle of the ceiling stayed turned on while doors are closed a few times in the past which drained the battery. This time it's the most severe I ever experienced.

The battery is also 3-4 years old and was working like a champ until a week ago.

maorsela

Holy crap, I just looked at the purchase history, I bought this battery in Feb 2012, so more than 6 years ago, had no idea it was that long ago, this battery worked like a champ, the frozen tundra of Chicago and the blazing Tucson sun.

Going to stop by an Autozone to get it checked.

fastnoypi

Glad they gave you a recommendation that works with Lexus all the time, hopefully they can sort you out. Your alternator was really put to work if you have always had issues with the dome lights. You're pretty lucky to have a 6 year old battery in that heat. I kept going through them every 3-4 years because the heat would evaporate the electrolyte when i lived in the valley. If there is any residual value, just turn that old battery in as a core. Keep us updated!

maorsela

I've only been to Tucson for 2 years now, prior to that the frozen tundra of Chicago

Heading out to Autozone during lunch-time.

Lexmus

No matter what AutoZone says, I would buy a new battery. Mine never last more than 3.5 years.

maorsela

I agree. I also noticed the dark deposits at the top of the battery in the photo I took, is it leaking?

Lexmus

Yes, it does appear to be leaking. But I am a little surprised if that is acid that you don't have evidence of corrosion on the terminals. maybe it just started.

maorsela

Yeah, maybe it just started and that's what's causing my issues? to be continued...

I did clean the terminals maybe 2 years ago or so, before I moved to Tucson.