Gen 3 audio upgrade, parasitic current draw killing battery.

Ok everyone... this is starting to get a little frustrating. I got the full system installed, 4 door speakers w/4-channel amp, 10” sub with mono amp. using an LC7i for my line out converter with the stock head unit.

So I have enough power, the lights aren’t dimming when the system is loud. Alternator is good (13.8-14.2v). Battery is a band new yellow top. I will jump the truck, drive around, if I only leave it for a short time I can restart the truck so charging is fine (I think).

When I leave the truck for a couple days when I drive my car, come back and it’s completely dead.

I used a multimeter between the disconnected positive and the battery terminal, but I get 0 amps, (however this was a shitty craftsman meter, my fluke got stolen)

I disconnected the power to the line out converter but it’s still dying.

I double checked the HU wiring and that looks good.

which leaves the amps, but the power lights aren’t on, but they can’t turn on without the LOC on (which was disconnected). My next step was to disconnect the main fuse for the amps, we’ll see if that works, but I don’t think it will.

I’m running out of troubleshooting ideas. Open to ideas if anyone has any.

thanks in advance!
JS

 

Have the battery Load Tested.

Install new battery terminals.

 

I threw a brand new Optima yellow top in there two weeks ago. Yellow tops are a deep cycle battery with 900ish CCA. I could do that but both batteries I had in there did the same thing. I don’t think that’s the cause.

 

Ya since the battery test is free, just thought I'd throw that out. Wouldn't hurt to change the terminals. I had a similar problem with a Jeep. I lost 2 batteries before I decided to change the terminals. Worked great after that.

 

Make sure your lc7 is actually turning off when the truck does.

 

Phoenix, you do have a point though, Toyota started using Aluminum for their harnesses and it there is always a ton of coronation on the terminals.

and 5nahalf, the LC7 is turning off

 

Try pulling the fuse for the amp every time you shut down the truck. I know it'll be a hassle, but it's possible that the amp isn't discharging quickly enough so it's still pulling current. If that ends up being the problem at least it's an easy fix. Relay on the power line.

I used to work in car audio (20 years ago, so I'm a little out of date), but whenever we had weird troubleshooting issues, we always went back to the grounding points as well. Grounds are more important than the 12V.

 

I find it hard to believe that you get 0 with the volt meter if you are using it correctly. Even the best systems have some drain.

My free harbor freight one works well enough for my purposes

 

I believe you leave the positive connected and disconnect the negative terminal, set your meter to amps, but check your fuse on the meter or your always going to get 0 amps. it should always be pulling at least .25 amps no matter what. if your getting 0 then its not hooked up right

 

https://www.wikihow.com/Find-a-Parasitic-Battery-Drain

 

you need a new line

 

Problem solved!

the culprit was a corroded headlight relay from the HID circuit. It was pulling .28A constant.

super hard to troubleshoot because I thought for sure it was the stereo because I had rewired the whole truck. Just happened to fail at the same time.

Note: best way to find a current leak is to put a meter between the battery terminal and the positive, then start pulling fuses until the current drops to zero and you’ve now identified the faulty circuit. (I was using a shitty meter before, could have saved a lot of time.