Parasitic drain on 2009 Tacoma TRD

I purchased my truck brand new in August 2009 and by December 2009 I start having this sporadic issue. In the beginning, I thought it was my stereo that was causing the issue since it would turn on and off by itself. Dealership replaced my stereo twice thereafter and still my stereo on occasions turns on and off, but now I’m not sure if the stereo is the issue.



3 weeks ago when I got home from work I turn my truck off and a couple hours later I peeked into the truck thru the window and notice the dash and instrument cluster were on by itself I than verified that nothing was left on in the vehicle, I than turn the truck on for the lights to go away.



Since this is an intermittent issue I sometimes do not see the dash /instrument cluster on but if the truck does not start in the morning (battery drained) I have to jump the vehicle to get a quick charge, But before inserting the key in the ignition, I notice that once the jumper cables are connected all the dash lights and instrument cluster in the Tacoma light up as if there were on previously.



Also on occasions the truck stays on when removing the key just like this thread http://www.tacomaworld.com/forum/2nd-gen-tacomas/183066-wtf-truck-stays-after-key-turned-off.html



Everything is stock I have taken the truck to the dealer multiple times when the truck was under warranty (Currently out of Warranty) and they were not able to replicate the issue. This parasitic drain does take its toll on the battery so now I’m on my third battery and probably going to get a fourth.



This issue seems to be more frequent in the cold weather rarely does it happen in warm temps and its January in Houston and there have been a couple of cold snaps.





2009 Access Cab Tacoma TRD

 

If you have a DMM (digital multi meter) or volt meter, you can go to your fuse box, start pulling fuses and putting your leads in where the fuse goes. If you get a reading, that means there is voltage going somewhere it's not supposed to. Then find out what circuit that fuse protects and go from there.

Edit: Make sure you do this with the truck off and key out of the ignition. Wait a minute or so after you turn off the truck to allow the computers to fully shut down.

 

so just the lights on the dash are on..is the instrument cluster on also?

 

Having the same issue on my dads cummins...the battery will drop from 12.4 to 12.3...sometimes will drop further, other times it jumps back up....do the parisitic draw test...although it didnt help me

 

I've heard of a similar problem with Hyundai's where the keyswitch is making contact after the key is removed. I'd look into that first.

 

X2. A faulty ignition switch could cause all the symptoms you described.

 

HondaGM –I did not know the terminology – so yes the instrument cluster is on.

 

Seems like your ignition switch, take it apart and take a look at it

 

I was thinking it may be a faulty ignition switch.

 

Exactly what lights are staying on? be very specific. Using that information we might be able to skip a lot of pulling fuses, which i describe below. if all the things staying on are on a single circuit, or controlled by one device, then maybe we come up with exactly what you need to check.

The method described above is not really a good way to check for parasitic draw. some circuits will always have voltage because some things need to stay alive.

this is the proper way to do a parasitic draw test:
- disconnect negative battery cable
- set digital multimeter to the amp setting
- connect the negative lead of the multimeter to the negative battery post, connect the positive meter lead to the terminal of the disconnected cable. any power your truck is using is now passing through the meter and can be measured.
- the vehicle has to be turned off, key out, preferably locked so it goes to sleep. although it will probably sleep eventually unlocked. can take many minutes for all modules to shut down.
- observe the meter to see how many amps are being drawn from the battery.
- a general guideline is if it's less than 50 milliamps then there are no problems. up to 100 isn't great but depends on the vehicle. In your case i would think it would be 1/4 to a full amp draw.
- if you are getting a high reading then you start pulling fuses one by one. every fuse in every fusebox. you will be watching the meter with every fuse you pull. if the reading drops to below 50 suddenly when a certain fuse is pulled, then thats the circuit which is being kept alive.
- use a wire diagram and back trace the circuit to find whats defective.

I haven't done this to a Tacoma, so i can't tell you what a normal reading would be unfortunately. It's way too cold for me to go find out for you haha.

The hard part is since it's so intermittent it will make it hard to catch. the good part is that it sounds like once it happens, it stays that way even after the battery dies, so you will be able to get set up and possibly catch it.

 

Thanks for your response. I'm going to see if I can get some pics when it happens again. I will try the parasitic draw test on Saturday.