Robert Taylor

Hey guys, haven't been on here in a while so hello again! Ive got an issue im hoping someone can give some insight into.

For the past 3 years or so Ive gone through/ruined a new battery every 6m - 1yr. I thought I had finally figured it out installing one of the special "AGM Technology" batteries the last time but this past weekend after just 5 months I burned through that one as well. This time I bought the absolute biggest AGM battery Duralast makes, took out the battery tray and pushed over my CAI to make it fit. My gut tells me the issue is coming from a faulty ignition or something of that nature? I say this because quite a while back the aftermarket amp/speakers started going out intermittently and progressively getting worse (playing music for less and less time) until the system did not play music at all unless the key was in the ACC position. Once the car started however, there was no stereo and as of now the stereo does not work at all but I believe that is my fault because I replaced the amp about 3 months ago and recently realized ive got the line converter wired wrong which I am going to re-look at that this weekend. But it doesn't explain the intermittence of the stereo not working and the numerous ruined batteries. Also about 2 weeks ago when I shut the car off the radiator fan stayed on (i read that can be normal?), I had to restart the car a few times until it turned off. Am I right to believe Ive got a parasitic drain on my battery somewhere? I bought a light indicator circuit tester to maybe tinker this weekend. I don't want to blow through another battery in 6 months, and id love to have my radio back. Does anyone have any ideas on where to start to fix the issue? Ive got the HFL disconnected btw. Any input or suggestions appreciated! Thanks in advance.

peter6

How you know battery is ruined? Because car doesn't start or did somebody actually tested it with proper tester? 80% of the time tester tells to try charging it first, and then it says whether it's good or not. Measuring voltage doesn't mean a thing unless you measure it under certain load.

If somebody actually tested it, and it said that battery is weak, then it's either not charger properly, or is drained too much when car is sitting.

If alternator is charging correctly (which doesn't simply mean that it outputs ~14V) then I would look for parasitic drain.

To properly test alternator you need some kind of tester. Multimeter is not enough. Either go to some shop and take a look at the printout from the tester, or use oscilloscope.

To properly test for parasitic drain, you need to measure current going out from the battery. Either use decent low amp clamp, or connect multimeter in series in 10A setting.

If you have stock radio and amp, I can give you diagram and point what to check first. Usually you want to check fuses and if amp is receiving "ON" signal. If you have aftermarket setup, then it might be harder.

Robert Taylor

Thank you for the reply!
i have had the alternator tested and when the battery problem begins the length of time it sits before needing to be jumped gets shorter. usually after 3 or 4 days itll always need to be jumped but when this last time this happened it was a weekend to a day then a few hours. The battery seems to always get charged as i never have a problem keeping the new batteries charged and everything is fine as long as the car doesnt sit for longer than a 3 weekend or so. I have a stock head unit and stock amp with the lci7 line converter connected to the original head unit and original amp wires and then connected to the aftermarket amp which runs wires to the speakers. Ill take whatever information or diagrams you might think would be helpful. I want to get it fixed, i just dont know where to start. Sounds like i need to trade the light tester in for an actual digital amperage reader to get to the bottom of it. I can relook at the replacement amp i installed and messed up but ive had this parasitic drain since before then for sure. With the speakers only working in the ACC position and the radiator fan not shutting off the other day do you think it could be something in the ignition? as in its not turning all the way to the OFF position when the key is removed?

vpasla1

You don't mention the HFL unit, that could also be causing the drain if it's connected.

Robert Taylor

@vplasa I do indeed have the hfl disconnected, it was one of the first things I did since this issue started.

peter6

You want to start with ignition switch, right? What car exactly do you have? Year, type-s or not, manual or auto?

Get yourself a service manual. That is a must have for any work, especially electrical.

If you got 2004-2006:
https://acurazine.com/forums/third-g.../#post15344256

If you got 2007-2008:
https://acurazine.com/forums/3g-tl-p.../#post16101585

Robert Taylor

thanks for the link! I've got a 2008 TL base model 3.2 automatic

thoiboi

I bet it's your A/C relay being stuck on and causing a draw... Besides the HFL, that's another current draw culprit.. I'd start there before the ignition

Robert Taylor

Id ask where the A/C relay is but with the manual (Thank you again) i should be able to find it. I just installed a new A/C fan this past weekend as ive been rolling without one for a while. I will certainly check to see if the relay is pulling any current first. Does anyone know how to check the ignition functionality and/or wiring? Theres a $30-40 set of electrical connections/wires in there that can be checked and replaced if needed right?

peter6

Robert Taylor

^^^^This is why I love yallz

I'll look at her tomorrow and report back.

Robert Taylor

Just wanted to give a little update to all who haveve pitched in. I was able to redo the sound system and have it working again. Ohh how its been missed. I also noticed that the LC7i was not turning off when the key was out of the ignition so I switched a few wires around and it now turns off when the key is off and no longer draining my battery! I still have some testing to do to ensure theres no parasitic draw but im not good with a volt meter. I did check every fuse under the hood though and there was no change so this weekend after doing some more research on mulimeters ill check the other fuses. I was getting a constant 0100 while it was set at the DC setting and like I said no changes when fuses were pulled. IDK if that reading is too high or not but i will look into it further.

DMZ

Have you checked the + battery cable too? At this age, it's likely corroded internally where you can't see.
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LoveMyTL-S

For me it was the A/C relay. Once replaced, no more battery jumping when the TL sits for a few days.

Synchro

That doesn't make much sense. Are you looking at DC current. Keep in mind current measurements are done with a different inputs than voltage on the meters. Look up some parasitic draw videos on Youtube to get a better idea of how to do it.

IRC, it should be below 50mA at full rest mode.