I have an 03 Subaru Forester 2.5X that we got from a family member. It has a low miles and a bit of mess but will make a great car for our college student.

I believe I have a battery drain issue. After watching (and crowning myself an expert) a Youtube video on how to diagnose parasitic battery drains, I'm pretty sure I narrowed it down to one circuit. The only difference I see between the videos is that my amp draw climbs - from 5 amps to 20 amps before my meters blanks out. The Youtube videos show a steady amp reading (dome light of a couple amps). Does this mean I have a large amp draw all the time? The samples shows draws of a couple of amps.

The No. 2 fuse in the main fuse box appears to feed two circuits that go through the Fuse Box under the dash. They include FB-8 (A/C control module, Audio, Clock, Combination meter (hot/cold switch), luggage room light, room light, spot light, and trailer connection) and FB-34 (Keyless entry control module, key illumination light).

Do I find each item (switch, connection, etc) and disconnect it individually to determine if it's my problem?

Thanks for your help.

Are you keeping the keyfob near the car when not using it?

My '15 Legacy has a drain if I leave the keyfob near the car. Not sure if that's a problem for '03.

Are you saying that you have a 20 amp+ drain?
That's a large drain if so. Many of the circuits have a fuse lower than that.
Even a 5 amp steady drain will run the battery down pretty quickly.

I had a Volvo that presented a battery drain that finally after a lot of work traced back to one circuit. It was a very tiny drain.
I'm pretty good with auto electrical systems but could not find a solid root to the problem. It also tied into the "always hot" side of the fuse box which would kill the battery after about two weeks if parked in a long-term situation.
Somewhere in one of the relays there was a small ground, but everything worked fine. The dealer estimated several hundred dollars+ of troubleshooting.

One of my old mechanic friends is better than me and suggested I not tear out the dashboard and offered a simple Rube Goldberg solution.

We knew the circuit didn't involve anything critical, so we switched the circuit affected wire from the "always hot" side of the fuseblock to the "on with ignition" side.

That solved the problem and we never saw any other issues.

Same goes for lost grounds. In many cases it is easier to establish a new ground on a circuit than to tear out the dashboard (or paying for dealers to search) in order to fix the actual ground.
Had this happen on a lot of old English cars-

(Hail, Lucas, Prince of Darkness)...

Does it have bluetooth?

Try disconnecting the alternator output wire and see what it does. Just for shits and giggles.

Oh, and remove the battery and Check for damage done by a screw left underneath when the battery was replaced

I'd start with pulling out some relays one-at-a-time. Maybe the A/C relay first.

Are you reading A (Amps) or mA (milliamps)? None of those systems scream 20A draw to me. How big is the fuse? 20A draw with everything in the off position isn't a parasitic drain, it's a short.

The keyless entry system will likely draw power after you turn the car off, possibly up to an hour (I know an hour is the cutoff on another brand). 5-20mA sounds about right for that.

quote:

Originally posted by Mikito:
Does it have bluetooth?

I had that problem with my Acura TL.
When I selected the HFL on the computer, it continually said "Booting." When I felt the map light console at the very front left corner by the rear view mirror, it would get very hot. So, it seems that the HFL malfunction was the culprit for draining the battery.


I disconnected the power wire going to the HFL. This immediately fixed the problem, since there was no longer be any power going to it.

Acura TL Dead battery/ battery draw fix

quote:

Originally posted by egregore:
Try disconnecting the alternator output wire and see what it does. Just for shits and giggles.

I agree, a good first start. I’ve seen several alternators cause big drains.

A friends onboard Bluetooth was consuming power and draining the battery.

quote:

Originally posted by 220-9er:
Are you saying that you have a 20 amp+ drain?
That's a large drain if so. Many of the circuits have a fuse lower than that.
Even a 5 amp steady drain will run the battery down pretty quickly.

This is my concern too. I'm not seeing a steady amp draw of a few amps. I'm seeing an escalating amp draw to where it exceeds my meter setting. It starts at 3 or 5 amps and quickly tops out at 18-20 amps. I believe I'm performing the test properly. I have an Ideal 61-310 multimeter. With dial set on DCA at 10A, I have the red lead on the left side port labeled "10A" and the black lead on the center port labeled COM. Am I doing it wrong? I believe I've followed the YouTube videos correctly. The fuse is rated at 15 amps.

I do not have bluetooth or a modern keyfob that constantly pings the car. While the car comes with power locks, the car didn't come with a Subaru fob. Last week I had an aftermarket fob synced to car by a tech. I do believe the problem predates anything he did.

I'll try the alternator wire trick. If I still have the amp draw with the alternator wire disconnected, can I rule out the alternator as a problem?

The battery is refreshed and is holding 12.33v. I know it should be around 12.6v, but not sure it will take more even after having the battery charger on for several hours. Last night after disconnected battery charger, it was 12.6 and this morning is was 12.33 and 12.33 at lunchtime. And I had the offending fuse pulled, so that makes sense while the battery remained the same. I attribute the 12.6 reading to fact that I had just removed the charger. When running, the battery jumps to 14+, which I understand is normal when the alternator is doing it's job.

The annoying part is that I'm on a 2 day business trip and won't be home til Thursday afternoon to tinker.

Anything aftermarket been added? Stereo? Amp?, fog Lights? Etc

quote:

I have an Ideal 61-310 multimeter. With dial set on DCA at 10A, I have the red lead on the left side port labeled "10A" and the black lead on the center port labeled COM.

And then what? Have you disconnected one of your battery leads from the battery and and used your multi-meter leads to complete its circuit back to the battery, hopefully with jumpers with healthy alligator clips. In other words, do you have your meter leads in series with one of the battery leads?

quote:

The fuse is rated at 15 amps.

Which fuse? The meter fuse? If so, you say you're reading 20A but not repeatedly blowing a 15A meter fuse? Not trying to be snarky, just asking for some clarification.

quote:

Originally posted by FRANKT:

quote:

I have an Ideal 61-310 multimeter. With dial set on DCA at 10A, I have the red lead on the left side port labeled "10A" and the black lead on the center port labeled COM.

And then what? Have you disconnected one of your battery leads from the battery and and used your multi-meter leads to complete its circuit back to the battery, hopefully with jumpers with healthy alligator clips. In other words, do you have your meter leads in series with one of the battery leads?

quote:

The fuse is rated at 15 amps.

Which fuse? The meter fuse? If so, you say you're reading 20A but not repeatedly blowing a 15A meter fuse? Not trying to be snarky, just asking for some clarification.

Yes, I've disconnected the negative terminal and have my multimeter in series.

The 15 amp fuse is in the main engine fuse box.

Swapped out the stock stereo for a Sony. Also, an Alpine 45w power pack was installed sometime ago and it seems to be spliced into the stock Subaru wireharness. When I added the Sony, I simply spliced the Sony harness into the Subaru connection. I believe the battery issues predates any of my work. I had a low battery several weeks ago and I thought I had left on the headlights.

quote:

I have an Ideal 61-310 multimeter. With dial set on DCA at 10A, I have the red lead on the left side port labeled "10A" and the black lead on the center port labeled COM.

Interestingly enough, the owners manual for this meter indicates it is not fused for the 10A range.
https://www.idlim.net/media/pd...61-310_manual_v2.pdf

When you have your meter hooked up as you describe, and if you open the door, do the interior lights come on?
This is assuming the interior lights did work previously.

If they do not, the meter is misbehaving. If they do, make a note of the reading. Interior lights generally do not exceed 10A.

Are there any aftermarket electrical additions on the car?
Which fuse box are you looking at? Under dash or under hood?
The under dash fuse box shows fuse 2 being for the heater fan. (Assuming this diagram is correct.) http://www.autogenius.info/sub...03-fuse-box-diagram/

Sadly this project is pulling fuses till you find the circuit that has the issue. I use a simple probe tester for that part as the actual amperage doesn't matter you are just looking for current...

quote:

Originally posted by Russ59:
I'm not seeing a steady amp draw of a few amps. I'm seeing an escalating amp draw to where it exceeds my meter setting. It starts at 3 or 5 amps and quickly tops out at 18-20 amps. I believe I'm performing the test properly. I have an Ideal 61-310 multimeter. With dial set on DCA at 10A, I have the red lead on the left side port labeled "10A" and the black lead on the center port labeled COM. Am I doing it wrong?

Assuming that



the meter switch is set to "DCA 10", the red lead is plugged into the "10A" jack, the black into the "COM" jack, what you're doing is removing the one fuse and touching the meter leads to the two fuse-holder connections: Yes.

But what you're saying isn't making sense. Being as the meter is rated for a max of 10A (thus the instruction manual pointing out it's a max of 10A and it being clearly printed on the meter as a max of 10A), I'm hard-put to see how it's measuring up to double that.

quote:

Originally posted by Russ59:
Yes, I've disconnected the negative terminal and have my multimeter in series.

You disconnected what "negative terminal" where?

quote:

Originally posted by Russ59:
The 15 amp fuse is in the main engine fuse box.

If the circuit was fused at 15A and something was slowly ramping-up to a 20A draw, it'd be blowing that fuse all the time. As in: Every time a new one was put in.

You're doing something wrong.

quote:

Originally posted by ensigmatic:

You're doing something wrong.

You sound like my wife!

Yes, I suspect am I and thought I may be wrong when I was getting that run up in amps. However, if I was consistently wrong procedurally, can I still suspect that fuse (No. 2 in the main fuse box) as the guilty circuit? It's the only circuit that didn't give me the run up in amps when I did the "pull each fuse separately" test.

I will try again on Thursday. Thanks for the response. I'll report back when I've got boots on the ground and not picking on CA bureaucrats.