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Need serious help determining the source that’s been killing my battery. I have an 07 TL w/Nav that dies after 1 day of sitting. It’s been ongoing 1-2 months. I have had the battery and alternator tested and both checked out good. I did a parasitic draw test with my multimeter and found that the car is pulling 750mA. For testing accuracy, I made sure to engage the door sensors and hood latch, lock the car, and wait 30 minutes for the car to completely turn off. After a little research on the forums about the HFL being a main cause of battery drain on these cars, I decided to disconnect to see if that fixed the issue. Unfortunately the car still died after 1-2 days. From here I reconnected the HFL and hooked up my multimeter to see what exactly was pulling this draw and how many amps it was consuming. After disconnecting the HFL again, the draw reduced to 520mA. I realized I had more than one component draining my battery at this point and the HFL only exacerbated the problem. I then began pulling fuses under the hood one by one to determine where the draw was coming from. In my case, fuse #15 (40 amp accessories fuse) was the culprit and the drain reduced to 30mA. Knowing the #15 fuse controlled several other fuses in the cars interior fuse box (5-9 I believe), i then proceeded to pull them. I ended up pulling every fuse in the interior fuse box just to be safe, and I found that the #5 fuse (radio) was causing the remainder of parasitic drain.
It dawned on me at this point, that several electrical issues I’m currently having might be related to the parasitic draw (radio controls on steering wheel no longer work while all other controls on the steering wheel do, and all the car speakers emit a low subtle white/static noise when the car is completely off/locked). First thing I decided to do was unplug the power to the amplifier (larger connection going into the amp). Lo and behold, the draw reduced down to 30mA (where it should be). To note, everything in the car is stock, no aftermarket equipment whatsoever.
With the car still off and the plug out, I tested to see if the radio was sending power to the amp when the car was off (via white wire), and it was.
Now from here I’m not sure what to do? Is a circuit in the radio
broken causing the power to be sent to the amp even when the car is off? I read on the Honda Element forums that the radio sends a signal to the amp to turn off, but if the radio doesn’t receive a return signal from the amp indicating it has shut down (due to amp malfunctioning), that power will remain on. Wondering if this might be the case also?
Besides replacing the amp and radio one at a time, I’m not sure what else to do. Can anyone please verify my theory or provide guidance what the next step might be. Any and all help would be greatly appreciated.
White wire is always power, through fuse #5. The ON/OFF signal from the radio is on Red/Yellow wire. No idea what's the rating on this, but use multimeter, not test light.
Thanks for the quick reply as well as the service manual, your awesome!
I’ll try this out tomorrow and report back.
I’m assuming the radio would be the culprit if the amp on/off wire has no power, causing the amp power wire to remain hot and the amp stay on.
However if it does have power, then the problem likely lies within the amp as it is no longer responding to the turn on/off signal, causing the on/off wire to remain powered.
Or is my logic about this incorrect?
I'm not sure how the communication between radio and amp works. Most likely Red/Yellow wire is hot when amp should be running, and is floating / pulled to ground when amp should be off.
I'm sure that radio is the one that "sends" the signal to the amp. Not the other way around.
Leave white wire be. It always will have battery power and it should. Measure just between Red/Yellow and ground.
If you measure 12V or 5V (on that R/Y wire) when "radio on key on", and close to 0V when "key off", I would assume that is a correct signal. Therefore amp is the culprit.
If signal on R/Y wire doesn't change depending whether key is "on" or "off" then I would assume something isn't right with radio.
If signal doesn't change, come back in couple minutes and recheck.
He wrote that pulling fuse #5 ended all parasitic drain. That's why he's digging into radio & amp circuit.
I only mention it because of this:
Originally Posted by Stickerguy20
Battery drain SOLVED on my 07 TL Type S.......
So here is my story on what happened. My 07 has 210k on the odometer, been a great car for the most part. My blueooth HFL has not been working for the past 6 months, just says booting up. And my navigation will come up Disc Read Error quite frequently now. I drive this car about 6 days a week and everything has been fine.
But 3 weeks ago, we were at the hospital for the birth of our child, and the car sat in the driveway for 6 days without being started. So, the day I go back to work, I walk out of the house and the key fob won’t unlock the doors. Battery is dead. I figured with it just sitting, and a year and a half old battery, that maybe it just was getting time to replace it. So jumped it off, and drove to work and drove around Monday to see if it would charge up. It did charge up, and I started the car a few times and it was fine. Tuesday morning, come out to go to work, dead again. SO, jumped off again, got it to work Tuesday. After work I went and bought a new battery for it. Fixed right? Wrong. Friday morning, went to start it, dead again. Jumped it off and got to work.
After reading about the HFL in multiple threads on here, I unhooked the bluetooth/HFL completely Friday during lunch. Drove it around the rest of the day Friday and it seemed like it was ok. One thing I did notice was that my Air Conditioning wasn’t blowing very hard out of my center vents like it usually does, but I thought nothing of it. So the next day I come out to start the car to go golfing. Guess what? Dead again.
So during the weekend, my dad and myself spend a little time checking fuses. We too, like many others on here, find that fuse 15 underhood is the culprit. And further investigation also brings up fuses 5, 6, and 7 in the under dash fuse panel because fuse 15 under hood powers fuses 5,6,7,8,9 under the dash. Fuses number 6 and 7 are the most drain. Fuse number 5 is a pulsing drain, but not very much of one. Something I stumbled upon while checking all the fuses and relays, was that when the car was running, if I BARELY PRESSED ON THE A/C RELAY, it would make a click sound down at the AC clutch. However, there was no sort of battery drain when unplugging the AC relay. So I set that thought aside and focused on the other fuses again.
So for the next day or so, I unplugged fuse number 15 under my hood, and layed it aside in the fuse box each time I got out of my car to preserve the battery. This worked to get me by for the day. After reading more and more, and finding that others are still having this problem, I found someone who had the HOMELINK go bad in their TL, so during lunch break I went and unplugged my Homelink completely. So Homelink and HFL are now unplugged. Well I go to leave work and the battery is still very sluggish, and at this point I’m getting very frustrated. So I leave work and go to turn some AC on. But it won’t come out of the center vents again. I hear it blowing hard, but it’s not blowing out of the center vents at all. So I remember the RELAY that was clicking. I drive straight to the parts store, and buy a $6.82 A/C Relay. Plugged it in and trashed the old one. Leaving the parts store, the car starts, and I also have cold air blowing out of my center vents again. That night, I left the fuse number 15 plugged in......
NEXT MORNING, I go outside to go to work. THE CAR STARTS GREAT! Turned over easily like it used to. I drive it that day, no trouble. I get home and cross my fingers as I HOOK THE HOMELINK BACK UP. Come out the next morning. THE CAR STARTS UP AGAIN WITH NO TROUBLE!!!!!
The problem was the A/C RELAY IN THE UNDER HOOD FUSE BOX. My *theory* is that the AC relay was doing something to the ac controls in the nav/radio unit and causing fuse 6 and 7 to draw a tremendous amount..... I don’t know how or if that’s even possible, but I hope this helps someone with the same problem I had.
Now also keep in mind that I do still currently have my Bluetooth HFL unplugged, but i don’t really miss it bad enough to spend $400 on a new one.
Well, after checking what I thought was the radio to amp on/off wire (remote wire) and not seeing 12v, I ended up taking the dash apart in order to access the rear of the radio so I could check the voltage at the remote output, only to realize I had checked the wrong wire going into the amp. Both wiring harness plugs that feed into the amp each contain a red/yellow stripe wire, however the wires in the smaller plug are of a slightly smaller gauge. On initial observation, I didn’t see the red/yellow wire
on the small plug, only on the larger plug. Another thing that thru me off was that that the power & remote wire were on separate plugs (power on large plug & amp on/off wire on small plug). When conducting the parasitic draw test, the larger plug was the source of the drain, so I thought nothing of the small plug.
However, after examining the wires at the rear of the radio and wondering why I had a remote signal (12v) out of the radio but not into the amp, I realized these wires were on separate plugs. I didn’t see the amp power wire out of the radio either which also drew my attention (should have remembered power wasn’t routed directly via the radio).
I immediately went to the small plug, located the smaller red/yellow wire, tested it, and found a 12v signal. At this point, the radio appears to be functioning correctly, and the amp isn’t responding to the off signal from the radio, this keeping it on at all times. I ordered a used OEM amp, hopefully it fixes the issue. I’ll will update after it’s installed.
Today was unnecessarily eventful, but I guess I learned a few things in the process. Lol.
Btw, I did trying replacing the a/c relay before all else even though it didn’t make much sense. In my case, it did nothing to reduce the parasitic draw
Well it dawned on my today that when I checked the voltage of the real amp on/off wire, I didn’t check it with the car completely off. I tested it again today and found that this wire has a constant 12v when the radio/car is on and off.
Is the amp on/off wire suppose to have 12v at all times, or only when the car/radio are turned on? If it’s the latter, than I think the radio is likely my problem.
Well it dawned on my today that when I checked the voltage of the real amp on/off wire, I didn’t check it with the car completely off. I tested it again today and found that this wire has a constant 12v when the radio/car is on and off.
Is the amp on/off wire suppose to have 12v at all times, or only when the car/radio are turned on? If it’s the latter, than I think the radio is likely my problem.
I think 12V should only be there when the stereo is on.
So if there is a 12V all the time, for some reason radio is staying ON, or at least requesting amp to stay ON.
Since you have a non-type s you don't have an active noise cancellation. I guess short between red/yellow and power is unlikely.
There is only one reason I can think of (besides radio being broken) - HFL has a function that will allow you to finish the phone call even if key is taken out.
You did disconnect the HFL, right? If yes, then the only thing left to try is to reset everything, by unplugging the battery for some time. You got the codes for radio and navi, right?
Last thing before ordering the radio that I would try, is to power the radio on the bench (by giving it just grounds and 12v power) and checking if that wire is still 12V.
Yes the HFL has been disconnected this whole time. I have the codes for the radio/NAV so I’ll trying disconnecting the power for 30 minutes or so and hope that does something. Is 30 minutes a sufficient amount of time or should I wait even longer?
Also, whats the best method to bench test the radio? Never done it before. I have some extra wiring from a previous install, and I’m assuming I just remove the battery from the car to use as the source, but several of the videos I’ve watched on doing this all used a wiring harnesses / pin connector when testing the radio. I don’t have an extra one laying around so I’m curious how I’d do this without attempting to contact the HU pin with the wire directly?
Yes the HFL has been disconnected this whole time. I have the codes for the radio/NAV so I’ll trying disconnecting the power for 30 minutes or so and hope that does something. Is 30 minutes a sufficient amount of time or should I wait even longer?
Also, whats the best method to bench test the radio? Never done it before. I have some extra wiring from a previous install, and I’m assuming I just remove the battery from the car to use as the source, but several of the videos I’ve watched on doing this all used a wiring harnesses / pin connector when testing the radio. I don’t have an extra one laying around so I’m curious how I’d do this without attempting to contact the HU pin with the wire directly?
You're going to have to figure out how to connect some pins directly to the stereo audio unit while you measure the Amp ON signal. Maybe you can backprobe the harness.
I confirmed my radio was the cause of the parasitic draw. It was no longer cutting the power to the amp on/off output once the radio turned off like it’s supposed to. Since the amp has a constant 12v supply at all times (from the fuse box), it relies on the amp remote wire (amp on/off wire) to power off, so that a break in the 12v power supply within the amp is created (or at least deactivated/put to sleep).
For others that may run into this problem in the future and your trying to determine whether the amp or radio is the source of the parasitic draw... don’t confuse the functionality of the small & large wiring plugs that are connected to the amp. Since the 12v power supply is on one plug, and the remote signal is on the other, unplugging either of the harnesses will cause the parasitic draw to subside since they both inherently cut power to the amp (just by different means). Removing only the larger plug (12v) when performing this test, may cause you to believe the amp has malfunctioned since removing its power supply would eliminate the drain completely; however without confirming the on/off status of the remote wire, you would never know for sure and either could be the cause. The remote signal (small plug) must be tested as well to verify if the 12v from the radio to amp is off. If the remote signal is off when the radio is off, and the parasitic draw persist, the amplifier would have to be the cause since it is has failed to internally affect a break in the 12v supply. If the remote wire remains on, as it did in my case, the amp will continue to draw power until the remote signal turns off/is fixed, or either plug is disconnected.
I ordered a used TL radio off eBay for relatively cheap and swapped it out already. The parasitic draw is gone and my car no longer dies. Replacing the radio also fixed the problem with my steering wheel radio controls not working, and they are functioning once again. The subtle white/static noise from the speakers has stopped as well. Be sure to look out for these signs if you experience similar problems in the future.
I’d like to thank you guys for your input and knowledge! It definitely helped to pinpoint my problem and fix the issue.
BTW, I believe the cause of my issue may be related to my two year putting coins in the cassette tape slot of the radio. It jingled when I took it out LOL. Keep an eye out for kids that age,
their a shady bunch!
