My wife has been experiencing a dead battery on mornings where her car has sat in the car for longer than normal without driving. Usually 2-3 says without driving.

We thought it was the battery (less than a year old), but all tests have come back negative for the battery. Using a volt checker connected to the negative battery terminal there is a draw on the battery while everything is turned off and no keys in the ignition.

While having the volt checker connected, I pulled the exterior fuses one by one until the light turned off. The one fuse that caused the light to turn off was the 40 AMP "Backup, ACC" fuse. What does the backup part of that fuse mean? The accessory outlets in the car shouldn't be on unless the key is in the ignition, correct?

Is it more likely to be caused by a bad outlet or a wire behind that is exposed and/or damaged?

Thanks for the help.

 

Most likely a bad HFL(Bluetooth module), which is designed to stay on for 30 minutes after the car's ignition is shut off. A bad HFL may not shut off, causing a continuous draw.
Does the HFL work? If the MID status says "Booting up" more than 5 minutes after you start the car, the HFL is bad.

You can test the draw by removing the HFL (very simple 5-10 minute job) and seeing if the draw disappears.

Check the "Bad Bluetooth" thread for more info.

 

Can you elaborate on what this is? My wife doesn't use the Bluetooth in her car and I don't drive it too often so I'm not too familiar with it.

Also, can you link to that specific thread? I can't seem to find it.

 

Update:

After removing Bluetooth HFL unit the draw test still fails.

Not sure what else to try at this point besides taking out the center console to try and unplug the 12v power outlet. That outlet shouldn't be drawing power unless the keys are in the ignition though. Any OTHER things that I'm missing that are controlled by that 40 AMP fuse for "Backup, ACC"?

 

An easy check to see if it was the HFL would be to touch the ceiling console where the sunroof button is. If it is warm to the touch even when the car has been off for a while, that is a good indicator (meaning it stayed on.) The system is supposed to stay on for I think it's 1/2 hour after the key is off. This works best early in the morning after the weather has been cooler though.

 

Thanks, but we already discovered the issue persists after removing the HFL.

 

Does the car have a remote starter or any aftermarket electronics-- alarm, stereo, radar detector, reverse parking sensors, etc.?

Aftermarket remote starters and security systems have caused issues with members' TLs.

 

I have a blitz safe iPhone charger/player installed to the back of the stereo.

 

^^ I see you posted on an older thread. I too have a parisitic draw, so I was searching online to see if mines could be the same issue. That "Backup, ACC" fuse seems to be a common problem on Odysseys. My HFL has been disconnected and I've noticed my car struggle to turn on like the battery isn't charged up. The battery is about 7-9 months old and I had it checked along with the alternator and both were good. My memory seat button stays lit all the time, but I don't see it being part of that fuse...

 

UPDATE:

Pulled every fuse in the car, one by one, and checked the draw.

It still exists. The only fuse to stop the draw is the 40 AMP "Backup, ACC" fuse under the hood. I really have no idea where to go from here and any help is appreciated.

I have a third party Blitzsafe iPhone charger/stereo cable installed to the back of the stereo, but that should be running off the same fuse as the stereo so I dont think that is causing an issue.

 

I have the multimeter connected to the Negative cable and the negative battery terminal.

This is what I am seeing from the Multimeter, see video here.

Is it normal for that number to be so high and then drop down by about half from doing nothing?

 

are you sure that you've unplugged the HFL module? I know its a dumb question but its one of those "dont ask how I know" deals.

What I've done was unplug the HomeLink (which is housed in the same plastic that have your overhead lights) thinking it was the HFL. I still had that characteristic 0.63 amp draw that would drop to 0.2-0.3 every 30 seconds or so.

To get to the HFL you need to dig deeper and unscrew 4 8mm bolts that hold the outside plastic bezel. You will find the HFL inside:

 

I sure hope you find the problem as I've been struggling with the same issue for years now. I've gone so far as to install a trickle charger as with a very good battery and full charge my car can only sit for 5 days before battery is dead.
I had one of those iPod devices installed as well, but removing it had no effect on current draw.
Surely someone has the wiring schematics and can tell us what the "backup, acc" wiring feeds.
My Acura dealer replaced a relay in the Center console as it was a known part issue with TSX's, but it didn't change a thing.

 

Yes....I took all of that out. No effect.

Did you watch the video at all that i posted?

 

I did - thats what prompt the response.

I had exact same problem, and also if I pulled that 40 amp fuse would kill the drain, narrowed it down to interior fuses #6 and #7. My tread on it:

https://acurazine.com/forums/3g-tl-problems-fixes-114/help-battery-drain-not-hfl-related-910864/


Its just odd that you are describing is apparently very symptomatic for TL's, and the usual remedy isnt working. Odd.

 

I'll take another look at it. Thanks.

 

So.....that bluetooth HFL said booting up for more than 5 minutes.
I removed it and rechecked Amperage. Here is a video

 

that is the same result that I have after unplugging HFL - 0.04 draw

 

I tested battery voltage last night and again this morning to check for drain.

Last night: 12.54
This morning: 12.45

Is that a significant drop overnight? Or does it look to be resolved?

 

Hmmm...I wouldnt rely on that. Battery voltage isnt really a reliable gauge. Even if the battery is on its last leg it will still show close to 12V. You can measure amperage across the battery terminals but most multimeters are not capable of handling that much current, and you still should measure in some discern intervals (such as 12 or 24hrs apart) to see if there is a drop.

The way you measured the draw (by disconnecting the battery and measuring the amps) is better DIY method. If that is your daily driver and you cannot leave it in the garage for a 2-3 days and then re-measure, go to Autozone/Discount autoparts and ask them to do a battery/alternator check. If you still have a significant draw, they *should* be able to detect it with their diagnostic.

Good luck!

 

My wife took it there before we suspected a parasitic draw. The battery tests great and is less than a year old.

 

I think that 40 Amp Fuse 15 feeds Fuses 5,6,7,8 under the hood. I tracked my leakage to Fuses 5 and 6. Total leakage is 200+ mA, enough to kill the battery in 3 days.

 

How did you stop it?

 

For what it's worth I was able to track my parasite back to the Xenesis car alarm/remote starter. It was drawing 530ma

 

Hi, sorry to write in an old thread. I am new here. I have 05Tl and have same issue. I removed HFL and i get same readings as you are getting on your multimeter after HFL removal. Did you get it fixed? It's very frustrating and embarrassing as i am constantly asking for boost from people.