Electrical drain - no clue

[VidRunner]

I've searched and googled for a month on this and seem to be chasing my tail at best.

2006 Limited. Several electrical mods - winch, fog hack, etc. And ... All fine for the last two years with NO electrical issues.

Woke up to 3am alarm a month ago. Tested battery, it failed, got brand new battery under warranty. Bosch platinum.

Ran fine and normal for two weeks. Again woke up to 3am alarm and rear wiper going for no reason. Disconnected battery and jumped in the morning. Ran fine.

Removed horn and sec horn fuses to save an argument with neighbors ... locked door physically with key (or, not fob). Hoped that would keep battery as is until the next day.

Nope. Drained to 7V for no known cause. Charged back up...

Have only reconnected to look for parasite drain.
Current shows 13-15 mA.

I'm not good with electrical.

- If multimeter is connected to measure current and shows 13 mA should any vehicle circuits work across that multimeter series circuit? EG, small things like the clock.

- Would the alarm be going off due to a parasite drain down below some trigger voltage point?

- If door switches are bad and alarm itself is the drain, what is best test? They all seem to work fine and show closed when closed and open when open. With dome light set to door, operation is 100% normal.

Sincerely losing my electrical mind ...

 

[VidRunner]

Having no idea what circuit is the issue, I noted the possessed rear wiper ...

All rear liftgate wiring looks brand new quality. No apparent shorts. But this seems weird:

With ignition in the ON position, pulling the 15A RR WSH fuse causes the rear wiper to move (constantly, like switched on). Even with the liftgate open. Is that a normal thing with that fuse being pulled?

 

[MikeinNH67]

I don't have your answers but best bet is to do a voltage drop test on each fuse. Basically you put your volt meter on it's lowest reading and put the probes on each side of the fuse. They should be under a half a milli-volt I thnk. If I recall correctly anything in the half volt range or more is suspect. This is with all the doors closed long enough for everything to be in a sleep mode. You may need to clamp the door switch so it thinks the doors are closed. If this isn't intermittent then you can pull the fuse in the suspect circuit and see if the issue goes away.

As for the alarm, it wouldn't surprise me if it went off as the battery was getting to a low state.

Here's a decent video:
YouTube

Here's a website with info:
Testing Parasitic Draw via Fuse Voltage Drop

BTW, one common drain issue across all vehicles is children putting coins in the radio.

Keep us posted.

 

[VidRunner]

Thanks Mike!

Ran thru all the fuses with the voltage drop check.
Came up mostly zeroes except for .5 mV on ECU B and OBD, and .3 on ECU IGN. That doesn't seem like a lot of draw but I also am missing the big picture clearly ... about 140 mA I think.

I'll let it sleep overnight and check it all again tomorrow.

Big thanks again for another approach to figuring this out.

 

[VidRunner]

Maybe solved

I should be glad that overnight battery voltage has been holding steady but I just don't like intermittent issues ... anyhow it is holding steady for now.

Because no circuit was an obvious issue, I removed the SECU fuse (underdash) hoping to at least keep peace in the neighborhood. Weirdly enough, with that out the main horn would still go off if the hood was opened with doors all locked. That got me thinking ...

I unplugged the hood latch sensor based on the weird alarm issue and a few posts about that sensor being an issue. That and triple scrubbed the battery contacts and it has been good two night in a row.

Maybe that latch sensor was it? Gotta love shotgun problem solving.


Now if anyone can explain why my VSC ABS reset won't work like it did last time ��...

Thanks again Mike for the voltage drop tip - def going to keep that in my back pocket.

 

[MikeinNH67]

I should be glad that overnight battery voltage has been holding steady but I just don't like intermittent issues ... anyhow it is holding steady for now.

Because no circuit was an obvious issue, I removed the SECU fuse (underdash) hoping to at least keep peace in the neighborhood. Weirdly enough, with that out the main horn would still go off if the hood was opened with doors all locked. That got me thinking ...

I unplugged the hood latch sensor based on the weird alarm issue and a few posts about that sensor being an issue. That and triple scrubbed the battery contacts and it has been good two night in a row.

Maybe that latch sensor was it? Gotta love shotgun problem solving.


Now if anyone can explain why my VSC ABS reset won't work like it did last time ��...

Thanks again Mike for the voltage drop tip - def going to keep that in my back pocket.

Intermittent issues are the worst. Good luck.

 

[Somnospeed]

REviving the dead.... I'm experiencing the same slow drain issue. If I go three days without driving my gen 4 4Runner, the battery will be completely dead, as in not even a click when the key turns or dome light flickering. I just put a brand new battery in a two weeks ago.
I checked a few fuses but haven't gotten to all of them, though judging by the responses I've seen in this thread and similar ones, fuses are not likely the issue. I plan to have the alternator tested, but not one person in this thread had a bad alternator.
I had a remote starter installed back in December, but not one time during the winter did I experience a dead battery. I have a 2nd car that I drive when it's nice out so the 4Runner can go 4-5 days without being driven, but this latest battery drain happened on less than 3 days.

I'm hoping someone has something to add or something I can check myself. I'm FAR from being crafty under a hood though, so unfortunately, I'm not skilled enough to dig deep into electrical systems.

Additionally, after I change the battery, I lost all power to the rear hatch. No rear wiper, no rear washer, no defogger, no lights back there. The "auto shut" feature works, but nothing else. Anyone have any suggestions about what that could be?

Thanks!

 

[wcjeep]

Pull the negative battery cable. Use a multi meter in amp mode. Measure the amperage draw. Be sure all lights are off.

Amp mode sometimes requires moving a test lead on the meter. How much is your amperage draw? Normal draw should be very low. Usually the stereo memory and vehicle computer. If it's above .5amp start pulling fuses until the problem clears itself.