Parasitic Draw Unknown Source

He wasn't really clear on if he had any voltage drop across any of the fuses or not. I would find it hard to believe there wouldn't be as pretty much everything that has constant power is fused.

 

Voltage drop isnt a tactic I use for parasitic draw.

I'm a fan of disconnecting large connections and working my way down from there. The connections on the BCM, both front kick panels and in the engine junction panel.

Tacoma is quite simple and usually isn't crazy hard to find.

 

Just thinking that either OP and the mechanic failed to carry out the test accurately, or there is something initiating current draw after the test is completed, etc. leading to him and the mechanic failing to find the draw circuit. @Bishop84 ’s idea is a more common sense approach of how to complete what I’m getting at.

 

Maybe you don't have a parasitic draw and the battery is just not as good as you think.

 

This is a good point! Just because it's "new" doesn't mean it's "good".
These scenarios are tough, because it could be a slight draw has drained the new/good battery repeatedly and weakened it,,, so OP could have more than one problem.

 

I had asked him the same thing and he replied if I correctly understood that he’s on his second battery and this one is a month old. I had a dying battery that mimicked parasitic draw symptoms this winter and it’s definitely always a possibility, but I think he could cross that one out - disconnecting the battery for a night and measuring voltage before and after should make that something that can be ruled out if need be at this point.

 

I wonder how he is measuring the draw, all the ideas have been excellent.
Maybe he should pull the connections off the battery, check voltage. Wait over night, check voltage. (Battery good or battery bad)
Now Put the amp meter between battery and cable and see the draw. Track it down.
Oh, do you have bed lighting? Is it on and you don’t know it.
Either way you are missing something. Repeating the same test over and over expecting a different result…. See dictionary for nuts.

 

Correct -- I did it multiple times with multiple meters. I don't really understand all the electrical stuff -- So my thought was it is impossible for there not to be a fuse without a reading, thus checking multiple times thinking I had to be doing something wrong.

 

Lol I am feeling a little nuts. I did multiple times because I was under the impression that one of the fuses would have to have a reading when testing voltage drop, I assumed I must have been doing something wrong. So I have done it multiple times with multiple different multimeters. Usually one watching the draw on battery while I am testing with the other. The battery is only 2-3 weeks old, but I will see how the voltage does overnight without connection on.

 

I have checked voltage drop across every fuse -- There is no current going through any of them. I have checked multiple times with multiple multimeters, all while monitoring the draw at the battery to make sure it is not an intermitent parasitic draw. My understanding was there would have to be a fuse with a voltage drop, thus my trying multiple times -- However I have been unable to ever get a reading.

 

Correct!

 

So to confirm -- You are saying monitor draw on battery and then start disconnecting large connections and see if it drops? Then start narrowing down from there?

 

In theory if the battery wasn't "good" -- I don't understand how that would have affect on reading I am seeing on multimeter? EX: A healthy battery would say the draw is only 50 mA, but an unhealthy one is saying it is 350mA. Or are you saying that it would lead to the battery being drained quicker by the draw? Genuinely asking here, I am just trying to learn.

 

I had a similar problem with my Chrysler minivan. Went thru 3 batteries in 2 years.

My mechanic figured it out. Fuel pump relay was faulty, and would come on after the van was off and fuel pump ran for hours.
In their infinite wisdom Chrysler made the relay a part of the fuse box, so the whole fuse box had to be replaced (national backorder of a year+). Mechanic wired an external, replaceable relay. It fixed the problem.

PS we had to replace the fuel pump a couple of years later. Extra hours of running finally killed it.

 

How are you connecting the meter between the battery and the car? I found this tool helped a lot when I was tracking down a drain. Allowed you to hook up the meter easily but switch between bypassing the meter or not without waking the computers up. Also fused just in case...

$24 Lisle 64970 Parasitic Drain Tester, One Size, Factory

https://www.amazon.com/Lisle-64970-Parasitic-Drain-Tester/dp/B00RGN5UAY?ie=UTF8

 

Do you have access to a thermal camera?
You can scan area for hot spots.

 

Just putting mutlimeter between battery and ground cable. That looks pretty handy -- Thanks!

 

I suggest doing the voltage drop test again.
Did you perform the voltage drop test on the fuses of both fuse boxes or only on the one in the engine bay?
There is one in the engine bay and one in the interior.
The interior fuse box is near the hood release lever.

 

Yes I did do both fuse boxes. I am open to doing it again, but will be the 5th time.

 

Do you have a clamp on amp meter so you can check individual wires?