Mazda 5 Battery Slow Draw/Not keeping a Charge

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2009 Mazda 5 GT
Got my first Mazda a couple of months back, a used 2009 M5 GT and I have been having problems with it starting/running out of juice. I really like the car as an around town family hauler but I'm not a car guy that can fix it himself and was wondering if anyone has had similar experience before I get bent over a barrel at the dealer.

I figured I might have a bad battery and after testing it at AutoZone I got a new one. Now one to two months later, Im having the same issue.

If the car sits for more than 24 hours it wont start. Ill hear a little noise, the air/radio actually come on if they were left on but the engine isnt starting and I have to jump it with a little portable battery supply. If the car has sat longer and I start to driving right after jumping, the power steering is rough and display/radio wont work until I let it sit in idle for a bit. If it's anything like it was with the previous battery, the problem will only get worse until the battery is completely dead after sitting for even shorter lengths of time and upon jumping it I'll be waking up the neighbors with the car alarm coming on every morning.

I just took the car to my local garage telling them I thought it could be a short (dome light isnt working and I havent tried replacing the bulb yet) or something else draining my battery. My only other thought was I've been using an fob from eBay to lock/unlock the doors and turn on the alarm since my car only came with one key. After keeping it for two days they said they couldnt fix, it could be something with the cars computer and I should take it to the dealership.

Help! Please!

Thank you
 
You can try unplugging a suspected device on the offending circuit and see if voltage goes to zero. For example if it's the dome light circuit then pop the assembly out of the ceiling with a flat head and unplug it. If it's the radiator fan circuit, unplug the radiator fan, etc. Just keep working towards isolating.
I also noticed that when I turn off the car sometimes the ignition switch is still in accessory mode. I notice this when I take the key out and try to lock the doors and it won't let me. There's a TSB on this issue I think. If you don't take your key out at the end of the day you might not notice this is happening.
 
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2009 Mazda 5 GT
Narrowed it down to the fuse that runs the dome/map lights and unfortunately my radio/map console. I can live without the lights and even the map but I gotta have my tunes. Do you think the most likely culprit is a bad wiring job at this point? Should I find a wiring diagram, put the fuse back in and start pulling wires?
 
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mazdadude

ZOOOOOOOOOM ZOOOOOOOOOM
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'16.5 Mazda CX-5 Touring
Is yours stock or has it been modified? (aftermarket Radio, alarm, radar detector, dash cam, etc..)

Your radio is supposed to have a little current draw, were you able to measure the AMOUNT of current draw? 50-100ma? more>?

Is there anything in any of your 12v (cigar lighter) Sockets/ front or rear?

Do all of your door/dome light switches work?

A failing alternator is also possible...What is your voltage at the battery terminals when the engine is running? Then test again while running, and with a big current draw such as headlights on high beam, fan on high, and rear defroster on.
 
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2009 Mazda 5 GT
Nothing aftermarket. Nothing the lighters. The dome light hasn't worked since I bought it used and I just checked the bulb and it looks alright.

I was doing the old fashioned draw test and pulling fuses. I think it was .5 to .7 when the fuse was plugged in and the multi-meter was on 10 amp setting.
 
As I mentioned why don't you unplug the dome light first to rule it out? Then unplug the radio assembly. Whichever drops the amps/mV you know is the cause.You can get wiring diagrams free from BBB industries or even autozones site. No reason to start a separate thread on that. Doubt it's the alternator based on the symptoms.
 

mazdadude

ZOOOOOOOOOM ZOOOOOOOOOM
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'16.5 Mazda CX-5 Touring
Nothing aftermarket. Nothing the lighters. The dome light hasn't worked since I bought it used and I just checked the bulb and it looks alright.

I was doing the old fashioned draw test and pulling fuses. I think it was .5 to .7 when the fuse was plugged in and the multi-meter was on 10 amp setting.
hmmm, the dome light thing could be your clue, perhaps try another bulb or you can test the bulb with your multi meter, and test the voltage available at the dome light bulb tabs, both in the "on" mode and "door" mode positions.

A possible problem could be a bad door jamb switch, and that kept the dome light on and car is not going into sleep mode.
 
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2009 Mazda 5 GT
As I mentioned why don't you unplug the dome light first to rule it out? Then unplug the radio assembly. Whichever drops the amps/mV you know is the cause.You can get wiring diagrams free from BBB industries or even autozones site. No reason to start a separate thread on that. Doubt it's the alternator based on the symptoms.
How do I disconnect the dome light etc? I've never done anything electrical with my cars more than replacing bulbs and fuses. Thank you.
 
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'07 Mazda5 GT
A failing alternator is also possible...What is your voltage at the battery terminals when the engine is running? Then test again while running, and with a big current draw such as headlights on high beam, fan on high, and rear defroster on.
This would be worth a look at. My '07 had low battery issues. Had replaced new batt but still would have low cranking power or would need a jump. Pretty much it needed an alternator. Get it tested before you're left w/o power while driving..
 
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2012 Mazda 5
i also have this issue with 2014 mazda5 gt. would like to know what the root cause is.
What is the issue? Battery drain but ok with the fuse off for the dome light?
Just run the diagnostic test in the YouTube video linked at the front, there are way too many things that can cause battery drain.
Also AutoZone will load test your battery and alternator for free, so do those test first before anything.
 
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2014 mazda5
Once in a while, if I left the car for 4-5 days, the battery would drained. But the last few days, I need to jump start it 3 days in a row.
I have an aftermarket android HU and a DVR with 4 cameras.

Will try the method from the youtube link this weekend.
 
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2014 mazda5
I check the fuses over the weekend. Nothing came up high enough; except the 'ROOM'; read 1 mV. That fuse is for audio, dome lights and alarm as well. I took the fuse out and I could not unlock the car using FOB.

Anyway, I left the car over night without the ROOM fuse. I am still able to start the car the next morning (have to put back the fuse). So that 1mV on 15A fuse might be troublesome. Or maybe it is the battery ? it is 2 years old from costco.
 
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2010 Mazda 5 Sport
1mV (millivolt) isn't right. Do you mean 1ma (milliAmps)? Voltage should always be 11.5v-12.5v. Electrical Current (Amps) is what you measure your drain in. Voltage is electron "pressure", Amps is amount of electron "flow". You want to measure the flow.

If it's 1 ma...that should not be an issue.

Did you check the drain from the Battery to a battery terminal first? With the car OFF, disconnect a battery terminal and put it in SERIES with the Multimeter. Set a high setting for AMPS and one lead in the Amps port. Anything above a few milliAmps is cause for concern. THEN you go to looking for fuses.

Also, when the car is OFF, what is the voltage across the battery terminals? A resting battery should be like 12-12.5v (I've seen 11.8v on a working battery).

When the car is RUNNING, what is the voltage across the battery terminals? To charge a battery you MUST have a higher voltage to "push" electrons into the battery from the alternator. You should get above 13v. Preferrably 13.5v-14v. Higher than 15v...and you're dealing with an overcharge scenario which will drastically shorten the life of your battery.

If your voltages at the battery are good...the alternator should be OK. If you have no parasitic drain from the battery other than a few mA, then it's looking like your battery needs to be load tested at any autoparts store.

EDIT:

Do you have corrosion at either of the battery terminals? If so, you have a bad connection at the battery. This will require a new terminal end installed or a new cable. Cleaning the terminal will help for a while, but the problem will eventually come back...potentially a year or so later. Take the cable off...bend it around..inspect it for cracks. Listen for internal popping and crackles which indicate internal corrosion. A car's starter needs a crap ton of current and if the cable is too bad, not enough current can go through it...then it will not start...but all the accessories will work...so often the battery is blamed.

Keep us posted.

EDIT: EDIT:

If you find a large parasitic drain at the battery...and you check for drain at all the fuses (many cars have MULTIPLE fuse banks in the engine bay and the cabin)...and the drain from all the fuses does NOT add up to the total....then you have a short somewhere else. I would start looking at anything wired directly to the battery...or a short through the starter.

-Mike
 
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2010 Mazda 5 Sport
There's plenty of YouTube videos out there for detecting parasitic draws on the battery. My personal favorite method:
https://m.youtube.com/watch?v=lRcj1fQcWwU
OK, I see where he got the mv from instead of ma. I don't know if this is the best way...It's an indicator, and I can think of a few problems with this approach. I'd still test at the battery to find the draw across the entire system.

And no, you don't need to "break out the expensive equipment", lol.
 
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2014 mazda5
I went ahead to bring the battery to costco. It is 2 years old, so they honored the warranty. Got a new one from them again. And 3 days and counting without troubles. Fingers crossed.
Occasional jump-start the battery might cause it to lose the hold capability.

I think the mazda; regardless model; has some parasitic draw somewhere. I read online there are a lot of similar issue.

Thanks for all help and information though.
 
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