Parasitic battery drain - Room Fuse - Advice?

[dcraig13322]

Issue: Car won't start due to dead battery after about a 1.5 days.

Found the problem: I measured all the fuses inside the car and in the engine bay that I could and the only fuse with any draw is the room fuse. It measures .6 with the 200m dcamp setting on the multimeter.

I unplugged the radio and it only measures .3 draw. Is that normal or do I need to keep digging?

What does your room fuse measure?

I found this on a different post:
Central locking, - no stuck button
Door lock actuators, - It doesn't make any noise
Audio unit ( stereo) - unplugged drops by .3
Instrument cluster, - blinks a lot to show the alarm is on...
Reading lights, - what is this?
Interior lights, - they turn on and off fine. Should I pull the bulbs and measure without them?
Boot/trunk lights, - None
Glovebox light, - None
Ash tray light, - Will check..
Dash lights/ panel illumination, - not on when car door is open.
Ignition switch illumination, - how do you check this?

[Jakeypoo]

I noticed my center dome light allows a small amount of current when in auto on mode. So I leave it set to off.

[dcraig13322]

Originally Posted by Jakeypoo I noticed my center dome light allows a small amount of current when in auto on mode. So I leave it set to off.

I'll try that and see if it lowers it. I also thought about buying LEDs to replace the standard bulbs with.

[Jeff23spl]

When you say .6 or .3 do you mean 600ma/300ma ? both would be high...remember a large and healty battery would be about 50-60A/h so droping 0.6A every hr would empty it in just few days...I think it should be below 100mA

There is a time to wait before testing. It may be 10min or more so you need to connect the meter and wait that time after....Maybe you can find the exact test procedure if you search google...

I have seen some problem where they replaced the BCM to solve the drain issue....It was on normal 3 but it could be the same....

[Yatta]

OP, I am not certain about the CX7, but can say that even normally my MS3 can draw between 180 and 250 ma parked, 300 seems close to to my observation but I would still look; depending on the state of your battery (age and terminals/wiring to it) this can be compounded... if your radio added 300 ma to this (is it stock?) I would start looking for ground issues as that seems like too much. What region do you live in (do you see sub-zero temps?) and how do you drive when you do (enough to charge it back up or?) Do you have keyless entry?

[dcraig13322]

Originally Posted by Jeff23spl When you say .6 or .3 do you mean 600ma/300ma ? both would be high...remember a large and healty battery would be about 50-60A/h so droping 0.6A every hr would empty it in just few days...I think it should be below 100mA There is a time to wait before testing. It may be 10min or more so you need to connect the meter and wait that time after....Maybe you can find the exact test procedure if you search google... I have seen some problem where they replaced the BCM to solve the drain issue....It was on normal 3 but it could be the same....

300ma is what I'm seeing. Every other fuse showed a .1 -- dam I had hoped I found it. A new ECM or computer doesn't look to hard to physically replace, but I'm worried about any kind tuning after.

[Coltzxli]

If you didn't want to go that route you could buy an AGM battery (larger Ah and CCA ratings) with a battery tender and hook it up every couple days over night for top offs

Just a thought

[dcraig13322]

Originally Posted by Yatta OP, I am not certain about the CX7, but can say that even normally my MS3 can draw between 180 and 250 ma parked, 300 seems close to to my observation but I would still look; depending on the state of your battery (age and terminals/wiring to it) this can be compounded... if your radio added 300 ma to this (is it stock?) I would start looking for ground issues as that seems like too much. What region do you live in (do you see sub-zero temps?) and how do you drive when you do (enough to charge it back up or?) Do you have keyless entry?

The radio is stock. I have left it unplugged since I found it took 300 ma for just that. The battery was just replaced before I bought it. Maybe I could just buy a larger capacity with about the same amps?? The terminals on the CX7 do not look stock with the fork, but they are and I can clean them.

I do live in MN, but I normally drive it to work so 15-30 minutes.

There is also keyless entry and an alarm system. Is there an easy way to turn off the alarm system to test if it is the problem??
I am going to pray out the dome lamp and disconnect it to see if that changes it.

Central locking, - no stuck button
Door lock actuators, - It doesn't make any noise
Audio unit ( stereo) - unplugged drops by .3
Instrument cluster, - blinks a lot to show the alarm is on...
Reading lights, - N/A
Interior lights, - I am going to pull them to see if this helps.
Boot/trunk lights, - truck light on ceiling
Glovebox light, - None
Ash tray light, - no ash tray
Dash lights/ panel illumination - not on when car door is open.
Ignition switch illumination, - I don't see one on when I turn the car on and the lights are on... Should there be?

I will try the light bulbs and clean the battery terminals.

[Yatta]

I am not certain you can disable the keyless entry.... the dome light seems to drain when in auto mode for some reason... I replaced all of my interior lights with LEDs... and noticed that it also dropped my parked drain... a lead-acid battery should hold a charge longer than a few days in our cars.. I went down this path when I converted from a battery to super-capacitors for starting and even that set-up seems to last longer than yours (and I am in Colorado so real winter as well). I have left it at the airport for a week in snow and it started right up. If your battery connections are all clean/secure I would have the charging system checked (or use a tester if you have access to one...) as well as the CCA/reserve for the current battery... a higher cap battery might solve your short-term symptoms only to have them return later.

[dcraig13322]

Originally Posted by Yatta I am not certain you can disable the keyless entry.... the dome light seems to drain when in auto mode for some reason... I replaced all of my interior lights with LEDs... and noticed that it also dropped my parked drain... a lead-acid battery should hold a charge longer than a few days in our cars.. I went down this path when I converted from a battery to super-capacitors for starting and even that set-up seems to last longer than yours (and I am in Colorado so real winter as well). I have left it at the airport for a week in snow and it started right up. If your battery connections are all clean/secure I would have the charging system checked (or use a tester if you have access to one...) as well as the CCA/reserve for the current battery... a higher cap battery might solve your short-term symptoms only to have them return later.

I'll look into the battery. I think I am going to just pull the fuse until it's warmer out.

[Jeff23spl]

BCM isn't the same as ECM, it is the module that take care of what isn't related to the engine...Not sure if it need reprog or not when replacing it....
There is also a possibility that a fuse box may have corrosion and leak some power between + and metal...3 first gen was suffering of it...

If you just drive 10-15min but need a lot of power to start the engine, you may not have time to fully recharge the battery and drain it a little more each day....and after few time it goes dead, even a brand new battery can get bad especially in cold weather...Peoples that don't drive enough sometimes needs a charger from time to time like mentioned above...

Yes you can get a larger capacity batterie that fit in the tray...when i replace one, i usually look for the biggest that fit there for our northern winter....(the real one with -30 c (-22F) on the thermometer) But regardless of the size, if you don't drive enough to recharge it, the problem will just come later...(For that case, you would look for the largest reserve in minutes more than CCA/CA but sometimes it follow each other)

For my dad beater (Pontiac montana 2001 that serve like a farm truck) i installed a 80A cutoff switch from a broken boosterpack between power source and main fuse. (starter remain on a separate circuit) i had no time to figure out the drain so we turn it off each time and it goes fine....Radio prog goes out but it is about that....for a CX7 GT you may have more device that lose the prog so it may not be a wise idea to lose it al the time...

Did you measure it with a clamp on device or in serie with a multimeter ? Usually you would get a more precise reading with a meter in serie for that low current...

Do you have a battery load tester ? (a 100A toaster) if not some place offer the possibility to make the test for you....you charge it 24hre than load it for x time and look at the voltage, if it drop below xxx, your battery need to be replaced.

[Yatta]

as mentioned, BCM runs all the other stuff (auto lights, environmental controls, personality stuff, keyless entry, etc..) and they have been known to cause problems like this... one note... if I recall correctly, the BCM is paired to the car and will likely take some dealership work to get one working correctly... the key fobs talk to it... or don’t if you replace it...

[dcraig13322]

I haven't pulled the dome lights again and then retested. It's been too cold. 1 or 2 more weeks or if I get bored I'll do it.

[Mylifeiseasy]

What battery is it? How old is it?
What are you recharging the battery with ?

[dcraig13322]

Here is the battery that's in the car. It is only a few months old.

https://ibb.co/gufNRS

[dcraig13322]

Originally Posted by Mylifeiseasy What battery is it? How old is it? What are you recharging the battery with ?

Standard alternator.