Opinions about Intermittent Battery Drain?

jonofmac · Post by **jonofmac** » 02 Apr 2010, 16:34

Hello,
I've got a '94 850 (the lower trim) and I seem to be having a strain intermittent problem with my battery.

It has been starting to happen more often, but my battery will be dead after leaving it to sit over night. So, i pull out my ammeter and check the draw, it's at 0.2 amps, which is way too high. Well I jump start the car and let it run and drive it around a bit to get the charge back up before I try to diagnose the problem. So after some driving i bring it back home and turn it off and check the draw, it's at 9.8 mA, which is perfectly acceptable. So i'm a little confused and start looking for any lose wires and find nothing. So I check battery voltage (stable 12.5ish) and leave it for the night, and come back the next day, and put my key into the drivers door to unlock it, well the drivers door unlocks, but none of the others do, so i get in and sure enough, battery is too low to crank. So I take out my DMM and check voltage, about 7.6V and check current draw, again it's in the 160-200 mA range. So i'm like ok then... Guess i'll just start pulling things out.

I open the fuse box and pull fuses 1 at a time, and not a single fuse caused a drop more than 1-5 mA, that is if they show any drop at all. So none of the fuses made the current pull drop into acceptable limits, so i just pulled all the fuses that made any noticeable difference and it was still in the 160-200 mA range. Frustrated, I took the cover off the box and started pulling relays, to which no difference again... So i then proceeded to rip everything electrical out of the engine bay, I took out all 3 ECUs, the ABS control module, and even went as far as removing the the SRS box (the one under the center console). And I'm still getting the high amount of drain. So i undid the battery connections and inspected them, they looked fine, and put it back on and checked the pull again, it's back at it's normal range, except a bit lower since i've pulled everything (like 2mA).

I jumped the car, let it ran for a while, and then let my mother drive it to work for a few days while her car was in the shop, it was fine for 3 days until it wouldn't start again due to low voltage.

I just found out about the relays on the inside of the car (by the pedals) and haven't been able to pull those yet because this problem is pretty intermittent. I'm thinking about getting a replacement battery and putting it in because this one has been drained well over 10 times to virtually 0 (and then the other times where i caught it at 9) and see what happens.

Does anyone have any ideas? this is driving me crazy. In terms mechanically, the car appears to be in tip top shape, the alternator does charge the battery, while thinking about it today, it's possible that the diode is leaking? but if it were leaking, why is this problem so intermittent!

When the draw is really high again, i'll go underneath and pull all the relays and see what happens, but so far, i'm at a lost with a car that seems to randomly kill itself.

I'm desperately looking for opinions, so please shoot if you have any.

Thank you,
Jonathan

Post by **misha** » 02 Apr 2010, 18:00

Do you have aftermarket alarm system installed or anything aftermarket... like stereo system,amplifier or something?

Also check your fuel filler door lock.If it's stucked it can drain battery after few days.

Does fuel door lock itself when you lock the doors and does it unlock when you unlock the doors?

Joe Hurless · Post by **Joe Hurless** » 02 Apr 2010, 20:23

I see this quite often... and after all you have been through, you may just want to jump off a bridge when you hear it... try this: Disconnect your glovebox light. This is a very common drain on 90's volvos, especially if the glove box is full.

Post by **jblackburn** » 02 Apr 2010, 21:30

I've been having problems with the alarm system not arming unless the rear door is given a firm slam. If it doesn't, it will drain my battery overnight and leave my lights on. When you lock the car, do the turn signals flash? If they don't, try slamming every door, hood, and trunk, and see if it will keep the battery charged.

Other than that, it sounds like you've definetly done all the investigating I would have already suggested to do.

jonofmac · Post by **jonofmac** » 03 Apr 2010, 00:00

misha wrote:Do you have aftermarket alarm system installed or anything aftermarket... like stereo system,amplifier or something?

Also check your fuel filler door lock.If it's stucked it can drain battery after few days.

Does fuel door lock itself when you lock the doors and does it unlock when you unlock the doors?

Thanks for the suggestion, I'll give it a shot when I wake up and see if the battery has died again.

I have no aftermarket anything except a radio. No external amplifiers or anything. It's not the radio because I actually unplugged it and took it out for a few days while this was happening. Nor do I have key-less entry, it's pretty basic. I have to use a key to unlock and lock it, but it locks all doors, I'm pretty sure that's normal across all trims. My question about the glove box light and the fuel door lock, do they still receive power even after a fuse has been pulled? I've been able to see the high current pull even after I've pulled all fuses. How ever, does anyone know if the central locking relay receives power regardless?
It sounds plausible. I know for a fact that it's not a regular interior light nor the trunk light, the glove box does seem likely, but I would think that pulling fuse 15 would kill it. I'll give it a shot though!

Thanks guys, keep em coming if you got em

I'll give all these a shot tomorrow when i get up

Joe Hurless · Post by **Joe Hurless** » 03 Apr 2010, 03:59

Let me clarify a bit. I learned about the glove box light drain from my father when he was first teaching me the ropes on volvo servicing. Several times a year these cars will come in saying the battery will not stay charged. This is usually due to a dead cell or a drain. When it ends up being a drain we often find it is the gb light, in which case we remove the box and disconnect, or remove the light. I have never questioned it because that's just how we do it because it works.

et3surge · Post by **et3surge** » 03 Apr 2010, 10:35

I have a similar problem currently and will try some of these ideas mentioned above. I have a feeling that several of these problems happen simultaneously which is why it feels like you are chasing a ghost. This seems to be because a lot of the small parts are starting to deteriorate at the same time.

Maybe this will help you to check, the rear Tailgate on the V70 starts to break down and the plastic pieces don't always work properly in the locking mechanism, in fact they just crack and start to fall out. What then happens is that you will intermittently make contact with the microswitch in the door lock and subsequently the lights on the side doors of the car...which are not visible when closed, stay on and drain the battery. I discovered this because my interior dome light kept staying on when all was closed, as long as it's in door mode. Eventually the entire plastic piece falls out and the spring also falls out of the lock and you need to buy the whole latch PN 9187990 again for a V70 1999.

One other thing I did in this car which seemed to help, I had high resistance right at the battery terminal + to my Starter +. So my DMM has a sharp point and I checked about 3 inches down the positive line poking through the red jacket and found no resistance while my other end was on the starter. I cut off about 3 inches and attached a new terminal, to eliminate any resistance in my positive line.

Personally while I find a rear latch used, I will remove all my door lights bulbs and my glove box light bulb and hope for the best.

One question on your methodology so I know how to check properly, from where to where are you checking for your current draw?

jonofmac · Post by **jonofmac** » 03 Apr 2010, 12:15

I was checking from the + battery terminal to the + cable, I would stick my ammeter in between. I had a system to prevent any power loss, because it seems that if there's any power disruption, it stops pulling excessive current. I'm about to go out and check these suggestions, thanks again. Lets hope for the best.

Either way though, should I just replace the battery since it's been drained so many times? I read somewhere that regular car batteries are made to withstand about a 2-5% drain before they should be recharged, and this battery has suffered several times from going dead.

jonofmac · Post by **jonofmac** » 03 Apr 2010, 14:05

Ok guys, so I checked all these things that you suggested. I removed the glove box light altogether. The fuel door lock functions perfectly, unlocks and locks as it should without a problem. I proceeded to open all doors, 1 at a time and close them with varying force to see if the interior lights would stay on, but nope. Everytime the door latched (even if it wasn't completely closed) it would still turn the lights off, i tried slamming and just barely pushing it closed, lights turned off every time on every door.

I also jumped the car this morning and drove it around for 30 minutes and brought it back home and let it sit for another 30, I checked the voltage while the car was running and it says 13.86-13.88V at idle (about 800 rpm), And checking with my ammeter it shows that 20-22 amps are flowing into the battery from the alternator, so I know for a fact that the alternator is working.

Thing is once I turned off the car, I checked the drain again, it's at 10.4 mA (this is pretty low, my Civic Si with an entire aftermarket stereo system pulls 34 mA when off) and checked the voltage on the battery. Initially it was 12.45, and it was slowly but steadily creeping down. After about 2 minutes it was at 12.33V. So obviously the battery has lost it's ability to hold a charge from being drained so much. Or perhaps a bad cell? I took it into Sears to try and get it replaced for free (free replacements if the battery craps out within a year) and they told me that the battery is fine and that there is a probably a problem with my car. I brought it to them a while back and they told me this (maybe 2 months ago), but now there has to be something wrong with it, perhaps brought on by the car draining it

but they won't need to know that.

I don't want to venture to say this is fixed because as I stated, it's pretty intermittent, but I'll go back to sears and get a new battery and I'll monitor the voltage and drain over the next few days and see what happens. Anything I might've overlooked?

Thanks!

jonofmac · Post by **jonofmac** » 03 Apr 2010, 15:14

Since I can't edit posts, I figured I'd post this.

I just went out to check the battery voltage and current after letting it sit. It's been 2 hours since my last post, and the voltage was at 10.4 volts... while the current drain still at 10 mA... So there is definitely something wrong with the battery. We'll see what sears has to say though