Battery drain! Help!

[gbrunin]

Ooooh boy, not looking forward to this. So I have a 2001 4Runner base. During the winter i was having issues with it starting, which i put away as a toast battery, but i bought a new battery about a month or two ago, and since then everything has been fine. Just last week i go out and truck wouldn't start, no crank, just a weird grumbling noise coming from the passenger footwell. I throw my battery charger on it while i go inside to get my multimeter, i test the battery and get 12.9v, I take the charger off and i get 12.1v. Now i'm really confused so i jump in and put the key to accessory and everything is fine all of a sudden. I take the key out and go to double check the battery voltage, which reads 11.5v and falling. And when i say falling i mean plummeting, 10.5v, 9.1v, 8.6v, etc. All the way down to about 3.5v or so.

So now to my question, the previous owner installed a remote starter, i took the dash apart a bit and i find that he twist and taped the whole deal, main loom is totally taken apart and wires are pretty much everywhere. Could this cause such a huge drain? I haven't used my remote starter for months and it's started like clockwork. Hoping someone will have some suggestions! I really don't want to have to solder up the entire remote starter.

 

[Paperjam]

REMOTE STARTS ARE GARBAGE!!!!

I take them out of cars all the damn time because of poor installation! If you don't need it, take it out, repair all the wires under the dash. I've seen problems all the way from shorts, drains, improper instrument readings (read the wrong fuel level and the customer ran out of gas multiple times). The problem isn't always the starter, it's the person who puts it in. If the PO wasn't a trained tech with access to wiring diagrams, I would pull that shit out so fast.

That sounds like a serious drain, 12.4v is a 75% charge, 12.6 is 100% fyi.

Your battery is probably cooked now, remove it from the truck and give it a 2a charge overnight and then check its voltage in the morning, take it to an auto parts place and have them do a load test on it as well. It should stay above 9.8v after 15sec of load. If not something has killed it.


Here is the method for finding which circuit is causing the drain.

How to Find a Parasitic Battery Drain: 9 Steps (with Pictures)

Pull the fuses for that remote start too as part of your diagnosis.

 

[TheDurk]

How long did it take to drain to 3.5V? You make it sound like it was pretty quick. I would expect SOMETHING to make noise, get hot, or release smoke if it were in the car.

My first suspect would be the battery. Rule it out, or in, by charging it with the car ground cable disconnected and watching the voltage for 24 hours.

Or try a different battery.

 

[gbrunin]

Thanks for the advice, the only reason i want to keep the starter is for the remote unlock, and it is nice in the winter (cold ass Canada). But obviously a working vehicle is more important than that. I have warranty on the battery still since it is so new, so if it's cooked i can get a new one. I've been having a lot of problems all leading back to things the PO did, and the ways he did them haha.

 

[KidVermicious]

Aftermarket wiring is always the first suspect when you're chasing a parasitic drain. But I'm with the Durkish one, a drain that fast should have started a fire, are you sure your multimeter is sound?

 

[gbrunin]

While it was draining there was nothing happening, not a sound. It was very quick, like a minute or so. I'm hoping my multimeter is good, it's a good quality one and i have no reason to distrust it. I'll pull the battery off and test it, maybe take it back and get them to test it. This is the first time it hasn't started since I bought the new battery.

 

[Paperjam]

Aftermarket wiring is always the first suspect when you're chasing a parasitic drain. But I'm with the Durkish one, a drain that fast should have started a fire, are you sure your multimeter is sound?

A really low battery will drain like that, they can also short internally.

Bad alternators can also cause a drain, bad diodes can cause negative a/c voltage to enter the system and cause the battery to drain while running too.

 

[baja1]

I fought a similar problem with my 2000, finally found a parasitic draw on my rear window defogger, I didn't even know I had a rear window defogger! pulled the fuse AND the relay. no problem since.

 

[calimobber]

The battery didnt instantly drain. Batteries take hours to charge. the high volts were from the surface charge, when you disconnected the charger it dropped back to its real voltage. Sounds like it might be toast but I would leave the charger on over night, then start the car and drive it for a little while.

Check the volts while its running. make sure its over 13v 14+ is where it should be.

normally if a battery is toast it wont start or do much once you disconnect the charger.