Parasitic battery drain help

RustyAb

New member
Hey guys, did a search and couldn’t find what I was looking for. I have a 15 SR5. I’ve put 2 new batteries in since fall last year, just drained too many times in winter and got them replaced under warranty luckily. I threw an amp meter on, and I am drawing 175 Milliamps drain. I just went through every relay and fuse looking for issues. I only found 2 problems.

Trailer brake fuse, once pulled I showed a decrease of 20milliamps. So I ended up just unplugging and removing my brake controller.

Now the Dome light relay, when removed will drop approximately 60 milliamps. I don’t have any bulbs out, haven’t done anything with cheap Amazon led’s. Should I replace every single bulb with oem sizes?

My question is, everything I’ve been told is that 50-60mA is normal. So any ideas where to look next for the rest of my drains? I’ve removed all aftermarket electrical mods. So it’s a pure oem system. I’m lost, thought for sure I’d pull a fuse and find it. Thanks!
 
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You’ve removed all aftermarket electrical mods? What were those?

Anything that I had tied in electrically. Disconnected my winch, took out my onboard air, ditch lights. Removed headunit and installed oem unit. Even pulled out my URD maf calibrator.
 
Hey guys, did a search and couldn’t find what I was looking for. I have a 15 SR5. I’ve put 2 new batteries in since fall last year, just drained too many times in winter and got them replaced under warranty luckily. I threw an amp meter on, and I am drawing 175 Milliamps drain. I just went through every relay and fuse looking for issues. I only found 2 problems.

Trailer brake fuse, once pulled I showed a decrease of 20milliamps. So I ended up just unplugging and removing my brake controller.

Now the Dome light relay, when removed will drop approximately 60 milliamps. I don’t have any bulbs out, haven’t done anything with cheap Amazon led’s. Should I replace every single bulb with oem sizes?

My question is, everything I’ve been told is that 50-60mA is normal. So any ideas where to look next for the rest of my drains? I’ve removed all aftermarket electrical mods. So it’s a pure oem system. I’m lost, thought for sure I’d pull a fuse and find it. Thanks!

There are things that are always on you cannot turn off such as the key unlock button sensors.

How long does your 4Runner sit with out running the engine and charging the battery? Any decent battery should be able to last a month with out charging. If yours are not, get a better or different brand battery.

If you go over a month, then put a battery maintainer to keep the charge up.
 
There are things that are always on you cannot turn off such as the key unlock button sensors.

How long does your 4Runner sit with out running the engine and charging the battery? Any decent battery should be able to last a month with out charging. If yours are not, get a better or different brand battery.

If you go over a month, then put a battery maintainer to keep the charge up.

The battery is not the issue. I’ve measured that I’ve got over the normal drain.
 
How long are you actually waiting before doing your test and pulling fuses?? Some systems won’t go to sleep for hours after shutting down. When you’re pulling fuses you might be resetting their time out. If you can find out how long it takes for the system to go to sleep on the 4Runner. At 150 milli amps it should take about a week of sitting around before the battery goes dead. You still might have a defective alternator, an alternator could still undercharge and not turn the warning light on since it will only come on when there’s nothing coming out of it.
 
Anything that I had tied in electrically. Disconnected my winch, took out my onboard air, ditch lights. Removed headunit and installed oem unit. Even pulled out my URD maf calibrator.
No aftermarket remote start then? I had a similar drain caused by a remote start in a Corolla a year ago or so. Pulling the inline fuses fixed it.
 
No aftermarket remote start then? I had a similar drain caused by a remote start in a Corolla a year ago or so. Pulling the inline fuses fixed it.

Sorry I forgot to say earlier, I had an accessorides remote start that has also been pulled. Also a pedal commander haha.

I’m just stumped, that if I pull the dome fuse there was no change. But if I pull the relay, I had that drop.
 
Sorry I forgot to say earlier, I had an accessorides remote start that has also been pulled. Also a pedal commander haha.

I’m just stumped, that if I pull the dome fuse there was no change. But if I pull the relay, I had that drop.
If you think it's related to the dome light relay, maybe a flaky door or liftgate switch? You could try turning all the dome lights to 'Off' with the doors open and measure, then have someone depress and release each switch one at a time while you watch for changes. Then close each door one at a time (to hold each switch closed in succession) and watch for changes.

Still thinking...
 
Mine would run down until I removed a Bluetooth device plugged into the ODBC port. It was taking power all the time.
 
Hey guys, did a search and couldn’t find what I was looking for. I have a 15 SR5. I’ve put 2 new batteries in since fall last year, just drained too many times in winter and got them replaced under warranty luckily. I threw an amp meter on, and I am drawing 175 Milliamps drain. I just went through every relay and fuse looking for issues. I only found 2 problems.

Trailer brake fuse, once pulled I showed a decrease of 20milliamps. So I ended up just unplugging and removing my brake controller.

Now the Dome light relay, when removed will drop approximately 60 milliamps. I don’t have any bulbs out, haven’t done anything with cheap Amazon led’s. Should I replace every single bulb with oem sizes?

My question is, everything I’ve been told is that 50-60mA is normal. So any ideas where to look next for the rest of my drains? I’ve removed all aftermarket electrical mods. So it’s a pure oem system. I’m lost, thought for sure I’d pull a fuse and find it. Thanks!


Here’s what I get for my 18 ORP. No remote start. I have made electrical mods, almost everything is on ignition power, other stuff is on switched constant power. Removed the OBDII interface dongle.

Hooked up the DVM in series with negative battery post wiring.

After getting out of the drivers seat, did not arm the alarm, and closing the door the dome lights etc are on for 30 seconds or so and it draws about 600mA.

Then it drops to about 135 mA and stays there for about 20 minutes.

Then the ECUs go into sleep mode and it drops to about 12mA.

I saw somewhere in a Toyota service manual that typical is 50 mA or less.
 
I have the same issue with my 1998. Measuring a 175 milliamps draining. When I check all the fuses and relays, no drop in the drain. Had 3 places check the alternator and all say it's good. Good luck and will keep following this post to see if you find a solution. And I'll let you know when I find mine.
 
I have a 2016 Limited with prox key. Takes about 30 minutes to go to sleep and rest around 50 - 60ma. I also have a remote start which is about 20ma, a telematics Drone unit which is 5 - 10ma but spikes to short bursts when talking with a cell tower, and a aftermarket radio with Maestro module at around 12m there. Dashcam also there which I havent measured but it does operate and record in an event with ignition off.

50ma should get you a week on a good, fresh battery that hasn't been drained before. Since I work from home for a while I was using a battery tender Jr with a quick disconnect cable out the front grill. I finally broke down and bought a hybrid Northstar battery from batteries+. The battery was well worth it since it's not a daily driver anymore.
 
Also fighting parasitic battery drain.

I have been looking for my parasitic battery drain too. If I remove the dome light fuse or relay, my amp draw goes down by 130 MA. The dome light relay tests good, but it is energized all the time. All lights in the system work normally! I’m thinking the problem must be in the body computer. I will probably just add a switch in the fuse circuit so when driving at night I can use the dome lights. Otherwise, the switch will stay off. The parasitic draw will take a new battery down to zero in about 4 days so I’ve been using a trickle charger.
 
I found an interesting issue that resolved my parasitic battery drain on my 2011 4runner!

1st, the battery was 7 years old...it was time for a new one. But 2nd...the brake/DRL light burnt out. So I replaced the bulb, but it still didn't work. There are two connectors in the assembly. The signal light that has all the wires going to it, and the brake/DRL light that inserts into a twist in harness with no wires(?). It ends up that somehow the signal light socket transmits the signal/electricity through the casing that it twists into. The signal light socket was just slightly unscrewed and was draining the battery down overnight. I'm talking like a millimeter of a twist...frickin weird! Runs like a top...had to share as it was a total fluke that I figured it out.
 
When I say "the assembly", I'm referring to the entire brake light assembly (brake, reverse light, and signal light enclosure). Really hope this helps others out!
 
...The signal light that has all the wires going to it, and the brake/DRL light that inserts into a twist in harness with no wires(?). It ends up that somehow the signal light socket transmits the signal/electricity through the casing that it twists into. The signal light socket was just slightly unscrewed and was draining the battery down overnight...

Any chance you can elaborate on this? I've recently had an issue with our 2014 SR5 killing the battery & want to check this out, but I'm not 100% certain what connector you mean.

Is it one of these?

57863f7c5af8f74deb6b46d2e19be027.png
 
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