parasitic electrical draw

[Jorge-789995]

I hope there is some conventional wisdom here that can offer suggestions.

I have an 02 V70 XC that recently developed the habit of a dead battery. The troubleshooting began. Please check my work and offer suggestions or questions for further clarification.

Battery goes dead in a day or maybe 2 depending on initial level of charge and temperature.
10 month old battery -Optima yellow top.
Alternator rebuild at a local shop 5 years ago.
The battery seems to be charging via the alternator and there is no issue driving for long periods after needing a jump. Car will start after being driven for 30-60 minutes after jump.
I've charged the battery by long drives (5 hours) and by a garage battery charger. The battery seems to be fine. 12.36V after and hour of parasitic draw and sitting in the cold for 48 hours. If I leave it connected, it'll be nearly dead the next day.

I put the mulitmeter on the the neg side of the batter in line and I get 2.03Amps of draw after the car has gone to sleep so to speak.

Alarm fuse (#38 I believe) has been removed for years.

I removed all the individual fuses in the rear cargo fuse box with no change to the 2.03Amps.
Same with the fuses on the left side of the dash. - no change to the draw.
I tried to check the alternator to see if it was faulty and drawing down the battery. It's not easy to get in there to remove the + cable, so I thought I'd try disconnecting the other end of the cable which I THINK is attached to the jumper post right behind the main fuse box under the hood. I also THINK the power feed into the main fusebox is on that same post. I removed those 2 cables and the draw dropped to 2.0-2.1Amps. I could have removed each individual fuse from the main fuse box, but I was thinking that this would rule out all of them or not and save the time. The results indicate that the majority of the draw is not coming from the alternator or the main fuse box assuming my assumptions were right - removing those cables cleared all the fuses in the main box and the alternator from suspicion.

I've searched around and it's rare to find a resolution to one of these parasitic draw problems. Sometimes it's a glove box light or a cargo door light etc, but there is always a fuse that points in that direction. More often there is no report that indicates what fixed it if anything.

Given that I have no fuse pointing me in the direction of the draw, anyone have any suggestions?

Is removing the 2 cables on the jumper post clearing all the fuses in the main box and the alternator?

I'm trying to work smart rather than brut force. It's cold out there this time of year.

thoughts?


thanks,

Keith

[Xfingers]

Check your owner's manual for the locations of all the fuses. The REM in the back storage compartment and the box on the left side of the dash have most of the fuses. Are there also a few located underneath the dash panel just below the steering wheel? I don't have my manual in front of me. Removing all the fuses from each box at once and then checking to see if you've still got a parasitic draw seems like a good approach, a lot faster than doing one at a time.

Another thing you can try is if you look at each individual fuse while it's plugged in place, I believe there are two tiny metal bumps sticking out of the plastic top of the fuse (where you also see the rating of 5, 10, 15...). I think you can also put the tips of your multimeter on these two bumps to see if that individual circuit is active. Maybe faster than pulling the fuse and then going to the battery to see if you're still drawing current.

Wish I could be more help. My first guess was that your alarm module was on its way out but if you already had the appropriate fuse pulled before your parasitic draw issue, then I guess that rules out the alarm.

[FirstVolvo]

I'm not sure disconnecting the cable at the jumper post disconnects the alternator and also starter motor. According to the wiring diagram I have the 12V bat connection goes directly to the alternator, starter motor and jumper post in the engine compartment fuse/relay box. It's not clear if this a serial type routing of the cable where if you discconnect at the fuse box jumper post it disconnects the starter and alternator. Assuming it doesn't I would think a 2A draw would produce some amount of detectable heat in the alternator (or starter) if that's where the draw is coming from and this assumes the battery isnt' already dead. You could just feel those area with your hand and see if there's any warmth there or use an infra-red type thermometer to see if you can determine anything. You can also measure for 12V at the starter after the jumper post connection is disconnected. If there's 12V at the starter motor with the post connection disconnected there's likely 12V at the alternator too. You can also measure for 12V at the back of the alternator if you can get to connection. I do think disconnecting thefuse box jmp post cable does take care of all the fuses in the engine compartment fuse box.

[Jorge-789995]

Update and possible resolution.

thanks for the help guys. Much appreciated. It's always good to talk this out with others.

I confirmed that pulling the cable from the jumper post behind the fuse box under the hood does disconnect both the starter and the alternator. I was checking voltage at the alternator before pulling the cable and I noticed it was only about 9 volts. I checked at the battery and again, 9 volts. This was after charging it overnight. I started thinking the battery might be bad and I think it was.

First rule in troubleshooting is you don't rule out anything without solid evidence to do so. I figured that since the battery was essentially new and that it was taking a charge, that it was not the problem. That was my mistake.

I swapped it out for a different battery and no issues starting 24 hours later. I had batteries plus test the battery and they indicated it was bad as well and saw 9 volts. I bought a new battery, topped off the charge and put it in the car today. So far, no issues so I think I'm in the clear. I'll post back if it dies again, but I think it was a bad battery. 10 month old Optima Yellow Top. I got a full refund so that was good.

I have no explanation why I was measuring a 2 Amp draw on the negative terminal.

Good to have the car back.

Thanks again,

[Brett San Diego]

Is the 2 amp draw gone with the new battery?

[FirstVolvo]

Update and possible resolution.

thanks for the help guys. Much appreciated. It's always good to talk this out with others.

I confirmed that pulling the cable from the jumper post behind the fuse box under the hood does disconnect both the starter and the alternator. I was checking voltage at the alternator before pulling the cable and I noticed it was only about 9 volts. I checked at the battery and again, 9 volts. This was after charging it overnight. I started thinking the battery might be bad and I think it was.

First rule in troubleshooting is you don't rule out anything without solid evidence to do so. I figured that since the battery was essentially new and that it was taking a charge, that it was not the problem. That was my mistake.

I swapped it out for a different battery and no issues starting 24 hours later. I had batteries plus test the battery and they indicated it was bad as well and saw 9 volts. I bought a new battery, topped off the charge and put it in the car today. So far, no issues so I think I'm in the clear. I'll post back if it dies again, but I think it was a bad battery. 10 month old Optima Yellow Top. I got a full refund so that was good.

I have no explanation why I was measuring a 2 Amp draw on the negative terminal.

Good to have the car back.

Thanks again,

The battery may have been bad but was it due to the parasitic draw every day/night the car wasn't running? Did you recheck the current draw with the new battery installed? If the battery was in a constant low state of charge it may have shortened the life of it or it could have just been a bad battery.

I finally looked under the hood of my car, and like you mentioned. disconnecting the two cables form the jumper post behind the fuse box does disconnect the starter and alternator. Looks like the battery positive cable comes up to the fuse box jumper post from the firewall area and the other cable connected at this junction is the one going to the starter and alternator.

For the two amp draw did you check for this current with the tailgate open and the rear cargo light was on? There's also the delayed power going to the CCM, DIM and other modules after the key is removed or when you first open the driver's door, With my car the power is present for about a minute with the drive door closed when the key is removed and longer if the driver door is opened. I can hear the little fan in the CCM running until this power is switched off by the CEM.
I've noticed on two of my near 20 year old cars the parasitic draw on the battery is increasing and probably due to the various electrolytic capacitors in the system leaking more. Could be something else too but there the current is increasing some and i have to charge the batteries more often if the cars sit for a week. It also seems like I have to replace the batteries more often.

[Jorge-789995]

Final update here.

At this point, I think it was just a bad battery. I had a 10 month old Optima Yellow top that I assumed was good. As a result, I looked at the car. As I mentioned I had the 2+Amp draw. I measured that draw with the tail gate open after everything should have shut down and went to sleep. I would leave it overnight and put the multimeter on or turn the multimeter on and I would see the draw. My meter has an auto shut off so I'd have to turn it off, then back on. The only thing I can think of is that the act of connecting the meter to the negative post and cable caused the car to wake up and draw that 2 amps. With the new battery, I can still measure the same draw, but the battery doesn't go dead so it must stop drawing at some point. I have left the car for 4 days in single digits and below zero temps and the battery has held so I think it was the old battery.

This is a lesson in troubleshooting for me. #1 Don't assume something is good because it is new. Test it and clear it like you would anything else. #2 Learn how to read the meter better. I think I got it right, but I am not a multimeter advanced user so that contributed to the uncertainty. #3 Think it through - attaching the meter caused the car to wake up and draw 2 amps. Then I measure 2 Amp draw and blame the car. I am half too smart for my own good.

In the end, the car is back and it's good to be starting every time.

BTW, this battle wagon is a 2002 with 250k on it. I like it more now than when I bought it nearly 20 years ago. It's been a good car - much better than I ever expected. Don't tell anyone though, I'd like to buy another one at a discount if/when this one dies. The goal is to hit 333k. At the rate I'm driving these days, that will be in 10 years.