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Lexus Parasitic Drain


Topic starter

Hi Scotty,

I have a parasitic drain in my 2004 Lexus ES330. aprox 193k miles.

The battery will be low or dead if it sits for a day/overnight or so.  I had the battery and alternator tested. They are good.

I replaced the alternator about a year, year and half ago or so. I replaced the battery back in August/September 2022. 

Things I've tried, after searching online, are: (note I tried these one at a time and let the car sit for a day or two)

Disconnect the factory amp, still had drain.

Pulled stereo fuse, still had drain.

Pulled the fuse for the drivers seat, still had drain.

Pulled the ECU-B fuse, still had drain.

Pulled DOME fuse, still had drain.

I disconnected the wires to the alternator, still had a drain.

No lights stay on after car shuts off.

I went and test the fuses in the engine bay, car was off, and the only fuse that had any voltage reading was the the D.C.C. fuse. It 
had a reading of 000.1 mV. So I pulled that fuse. Let the car sit over night and it fired up. No problems .

From what I've found online -
D.C.C - "All components in “ECU−B”, “RAD NO.1” and “DOME” fuses"

So now I'm not sure what to check/look for.  Any idea whats connect to the DCC fuse that could cause the drain ?



5 Answers

See my video fixing battery. Drain on your car Scotty on YouTube

Hi Scotty,

I've seen that video. Thanks!

I've isolated the drain to the D.C.C. fuse in the engine bay fuse box.

I've pulled that fuse out for now. No parasitic drain.

Not sure what the exact source of the drain is but at least its not draining.


Posted by: @hairball

I've isolated the drain to the D.C.C. fuse

what is DCC?


I think it stands for Direct Current Cut.

most of a vehicle's electrical circuits are direct current.
Does that mean this fuse cuts off everything?


From what I could find out, it only cuts off certain circuits in the car.  It is removed when the car is being shipped and reinstalled by the dealer.  It seems logical that there is a parasitic drain on one or more of the components this fuse serves.  If you google Lexus DCC fuse, you'll get about fifty or so answers from various forums dealing with the same problem on Lexus, Toyota, etc.

Topic starter

Yeah I did a search and quite a few possibilities. Seen one that mentioned something about door lock solenoids, not sure if thats my issue or not.  

This will be "fun" to track down.