My 850 wagon is drawing (if the battery is charged) around 6 amps. So i started messing with the fuses, relays, anything with a plug. All fuses in the fuse box do nothing, same with relays, also relays under the dash don't change anything. Checked rear bulb failure relay, secondary air pump, radiator fan relay, fuel pump relay. Nothing changed. Last 3 to check is in the steering wheel, and the relays for the climate control. Cant find anything about the steering wheel online, in the wiring diagram it says its the DIM/DIP regulator. Any ideas on how to get to it? Anything helps, thanks!

ive also taken power off of the alternator and starter to see if that would change anything.

 

6 amps? Do you mean .6 amps? ( 6 amps is a big number)

How are you measuring this. With an inductive ammeter? With a volt/ohm/ammeter wired in series with the battery?

How long does it take for the battery to be weak/dead?

Not knowing what year your car is - on some 850s the glove box light switch is in the left corner and the latch is in the center, the glove box door warps and does not shut off the glove box light. Take the glove box out and remove the bulb if so.

 

Yes i meant .6 amps, forgot the point😅.

Sorry, its a 96

I have the power going through my multimeter, when the battery is fully charged the car draws .6 amps, when left for a day or two it reads about .4 amps. Ive already checked the glove box and have a felt pad to close it all the way.

After three days it had a hard time starting, Ive been keeping it charged since.

 

If you've got a wiring diagram, you're advanced beyond internet help, I'd say. I hope you figure it out. I will say the diagram has a nice power distribution section. The harness has lots and lots of connections that aren't easy to get to.

 

My Volvo 2004 XC90 has a battery leakage of 5+amps--Yes, 5,000+ milliamps. I have my multimeter on the 10-amp scale and in series with one lead on the negative battery terminal and the other lead on the negative cable (unconnected, of course, to battery terminal). I have removed all fuses one by one and the leakage remains 5+ amps. The battery goes down overnight and actually goes down in few hours. I can start the car and remove the cable from the negative battery terminal and the car continues to run. Measuring the battery voltage with both positive and negative cables in place and the car running gives a voltage of about 14.4 volts. The alternator will charge the battery after running the car for a few hours so the alternator appears to be okay in that respect. However, I read that the diodes can go bad and allow the alternator to leak current even though it continues to charge the battery. However, I cannot get to the alternator to remove the battery cable to test whether the 5-amp leakage goes away when measuring the drain. I've run out of ideas. This Kentucky Hill Billy would welcome any advice.

 

DO NOT DO THAT

The battery acts as a capacitor and you can fry your alternator. That was ok in the 1960's when we had generators - but not since then.

If you have a drain, a parasitic draw on your battery you need a non contact ammeter. Something that clamps around the positive (or negative) cable to measure current flowing. There are many control units that stay active whenever you just look at the car - if you want reliable data, open all the doors and trunk, and latch all the latches (so everything thinks it's closed) , take the key out and press the lock button on the remote. Attach an inductive/non contact ammeter and wait. Anything you touch, a fuse, might turn a module on and give you a false reading.

Power to most everything in controlled by the CEM. Leave the door open - the dome light turns off after x minutes. So - any aftermarket stuff installed? Alarm, lojack, gps tracking device from the stop and pay car lot?

 

Thanks for help hoonk. I don't have a non-contact ammeter yet but I will look for one. If I understand correctly you are thinking that one of the many chips in the car is drawing excess current? It is my understanding that the normal drain on a battery will be less than 75 milliamps if everything is okay. It doesn't take long to discharge the battery when the leakage is 5 amps.

 

It's an unfortunately complex machine.

I've said it before, whatever is taking that 5 amps will get HOT. As hot as a 60 watt incandescent light bulb.

I am a little skeptical about the diode being bad and the alternator putting out 14.4 volts, but that's a lot of amps and it's unfused, so that does certainly narrow it down. The alternator is one good place for that to happen and not melt anything. If you have a wiring diagram of course you could look for unfused stuff. Then again it may have some more fuses you haven't found yet.

 

Firebirdparts: Thanks for help. I tend to agree that an alternator putting out 14.4 volts seems to discount even one diode being faulty but it is still worth a test I suppose. I have found 4 fuse panels but only 3 of them have fuses. They are located in: engine, left side of dash, left side of cargo, and under the steering wheel. The one under the steering wheel has no fuses.
I failed to mention in the reply to Hoonk that I have not added any aftermarket devices to the car.
I wanted badly to check the alternator to see if the 5-amp drain vanished by disconnecting the alternator cable from the battery but it would take most of the day to remove enough stuff to give me access to the alternator. There is not enough space to get my hand on the nut that holds the cable.

 

When I bought my 850 I contacted the original owners son and he mentioned the car flattened the battery if left for a while. I had to fit a new battery last year and top it up once a week with my CTEK. which takes a longer than topping up my XC90 battery when left for the same length of time. So today I decided to check for parasitic draw and was please to find the 850 was only draining 0.22amps when asleep

 

The alternator B+ cable terminates at the starter. Disconnect the alternator there.

 

Sounds like a trip to Harbor Freight is in order :-)

https://www.harborfreight.com/digita...ter-96308.html

 

For those folks who have helped me, I wish to state my errors and my successes on finding the battery leakage. On, Monday, 9 May 2022, I made some measurement discoveries. After listening to a number of videos on how to find the location of battery leakage, I realized I wasn't waiting long enough for the chips to go to sleep. What I originally thought was a leakage of 5+ amps settled at 1.26 amps after waiting 15 or 20 minutes for the chips to settle. Of course, 1.26 amps is still too high to protect the battery from discharging overnight. The leakage was still 1.26 amps after disconnecting the starter and alternator at the starter solenoid. Hoonk stated that both the battery and alternator cable could be disconnected at the starter solenoid which was helpful. This disconnection indicated that the leakage was not due to either device. Thank goodness I didn't have to replace the alternator. That would be a couple days work for me or more. My earlier statement that I had removed all the fuses and none showed the current to vanish was in error. You must wait 15 to 20 minutes each time after removing a fuse or you will not know whether that circuit contains the leakage.

I then changed my measurement technique. Instead of measuring the current between the negative battery terminal and ground I began measuring the voltage across each fuse. A fuse has a low resistance, maybe milliohms?, so the voltage drop across a fuse that is leaking will only measure in the millivolts. Otherwise with no leakage in a fuse the voltage across the fuse will be essentially zero millivolts. The fuse that went to the sunroof was showing 3 or 4 millivolts instead of zero. I reconnected the battery and opened and closed the sunroof. I then measured the current between the negative battery terminal and the negative cable (ground) and after about 15 to 20 minutes the current dropped to about 51 milliamps. The sunroof was causing the leakage. Apparently it was not completely closed as I remembered that I had some water on the carpet one morning.

 

Still looking for the draw! Pretty much tore the car apart

it dies alot slower now that its warm out. The other day the headlight went out and i found the plug was welded shut, I've replaced the plug and light, haven't checked if the draw is still there. Going to go through the fuses again, maybe i missed something.

after seeing what mich said ill see if waiting 20 minutes changes anything

 

Nothing changed for a while, but the starter started lugging. Turned out It was the starter, took it apart, lots of dust and grime, cleaned it out, cleaned the brushes and used scotchbrite on the armature, it was scratched up pretty well, made it smooth and no more power draw, starter moves a lot faster now as well.