Mazda 6 Forums banner

1 - 20 of 26 Posts

·
Registered
Joined
·
466 Posts
Discussion Starter #1
For the past couple weeks, my MS6 has become a bit harder to start. If the car isn't used for two days, the battery gets low and the car barely turns over if at all. Even when fully charged, the battery still dies after a couple days.

The battery is a four year old Die Hard Platinum. It tested fine at Sears and O-Reilly's. At Sears, they said the alternator was putting out 13.7 volts and the diode is fine.

The car is stock with nothing recently added or changed. It just started acting this way. Any idea what could be causing the problem?
 

·
Registered
Joined
·
1,287 Posts
corrosion my guess.
if you say the battt is good, ignition ground wires?

but still, a 4 yr old battery.
 

·
Registered
Joined
·
466 Posts
Discussion Starter #3
The terminals on the battery are good. Both stores tested the battery and said it was fine. I haven't checked the grounds yet though. The battery was fully charged by Sears on Wednesday of last week.
 

·
Registered
Joined
·
1,287 Posts
does it start fine once they recharge it or does it not make a difference?
 

·
Registered
Joined
·
466 Posts
Discussion Starter #5
It starts fine after recharging/running around town. It just happens when sitting, making me thinking there is a current draw somewhere.
 

·
Lowspeed
Joined
·
6,280 Posts
often let it set for a few days? Next time it's gonna sit, disconnect the battery.

Reconnect when ready to start again after a few days. If the battery, the symptoms will remain, if a drain from the car then it should start right up...
 

·
Registered
Joined
·
269 Posts
Just do a simple parasitic draw test with a multimeter. Google the proceedure. Once its connected, start pulling fuses one by one to see if the draw changes.

I just did this the other day to diagnose a draw on my batt (but I have a complex stereo system). Worked like a charm.
-a
 

·
Registered
Joined
·
466 Posts
Discussion Starter #9
There is no aftermarket stereo in the car and nothing else that would cause a draw. The battery this morning read 60% per my charger and it is charging now. The only electronic item in the car that is not functioning properly is the monroof. It opens, but doesn't always close.

I thought about doing a current draw deal by pulling fuses. I have a multimeter, so it shouldn't be too hard.
 

·
Registered
Joined
·
269 Posts
There is no aftermarket stereo in the car and nothing else that would cause a draw
Note: just because you dont have aftermarket electronics does not mean there is nothing to cause parasitic draw. Any electronic item in the car - OE or aftermarket CAN and DOES cause draw (i.e. the PCM). Some draw is ok, and if any of those items have some sort of short in them (i.e. possibly your moonroof), there will be excess draw.

Also, where do you park yor car over the weekend? Is it an appt. building? Lots of nearby activity with other cars/people walking by the car? Keyless entry systems "listen" for the chip in the key fobs. And every time someone with an RF key walks by, the keyless system goes active to see if the signal is its long lost soulmate. If not, after a few min, it goes back to sleep. If lots of nearby activity, the system may be in full active mode, and cause exess draw.

-a
 

·
Registered
Joined
·
466 Posts
Discussion Starter #12
The car stays parked in my driveway. It has been parked on the same side of the driveway since I brought it home over five years ago. When I meant there was nothing else causing the draw, I meant aftermarket items. I don't even have a radar detector plugged in.

This just started happening two weeks ago. It felt a little hard to start after being parked for a weekend. One month ago, it was parked for a whole week while we were on vacation and it started right up. I have made no changes whatsoever to the car in the past month. No lights left on, no stereo systems installed, not even an oil change. The only thing it has gotten is a full detail, and that was just at the end of last week.

I'll do a current draw test as outlined (thanks Ti) and see what happens. It's just weird that is started happening so randomly. Once it was charged, I ran an alternator test through my charger and it reported 13.7 volts while running and with the lights on.
 

·
Registered
Joined
·
106 Posts
Trying to track this down can be really a pain. I had an old Ford Bronco 4x4 up when I lived in Mass. Every once in awhile the battery would be dead. Charged it up and it ran fine. Turned out to be a relay for the rear defroster that stuck on sometimes. When it happened to stick on, it drained the battery overnight. I did the parisitic drain procedure and found the fuse responsible, then tracked it back to the relay which was still in the closed (on) position. A lot of work and having the wiring diagrams to follow the current draw was really handy

Good luck....
 

·
Registered
Joined
·
466 Posts
Discussion Starter #14
I'm seeing a steady 0.33 mA with the key off. Is that really that high? I charged the battery to 100% this morning and after a 10 mile drive today, it is now at 60%.
 

·
Registered
Joined
·
1,287 Posts
does the car ever die once its running? I mean there should be a recharge once the alternator kicks in.

kill the battery again, jump it off another car and see if the car dies after 10-15 minutes of idle. Prolly less time.

Possible alternator is shit? or at the very least continuing to pull after the car is running?
 

·
Registered
Joined
·
269 Posts
I'm seeing a steady 0.33 mA with the key off. Is that really that high? I charged the battery to 100% this morning and after a 10 mile drive today, it is now at 60%.
Sounds like a bad alt to me. or the tool you are charging/measuring with is inaccuarate?
 
  • Like
Reactions: jm211

·
Registered
Joined
·
1,287 Posts
I agree.

Alternators on this car are big money. almost the cost of an accessport... :(
 

·
Lowspeed
Joined
·
6,280 Posts
Since the Alt has been tested as good, and you're getting 13.7 while running, I'd spend my time looking everywhere else.

I haven't actually read all through the how-to posted earlier, so this may have been noted, but remember that you have a main fuse box right there at the battery. You may be able to remove major chunks of the system and see if the draw changes that way, easily.

also, our security system is a power hungry SOB. Not sure what it's draw actually is, but wanted to just mention that the car, when all is good, has a high draw on the battery.
 
  • Like
Reactions: jm211

·
Registered
Joined
·
466 Posts
Discussion Starter #19
According to the link you posted, standard is 0.2 mA. I pulled every fuse in the main and kick panel blocks and nothing changed.

The battery is now at 100% per the charger (Die Hard Electronic), and I'll test it in the morning. I'll do the same thing tomorrow night, except leave the battery disconnected.
 

·
Registered
Joined
·
20 Posts
My '06 MS6 has been doing the same thing for a while now. Left sitting for a week or more the batt (only a year old) goes totally dead. Charging, Dashhawk says 13.7 or 13.8V. Turns over slowly even after sitting overnight. I was going to try the fuse pulling test soon, but it's interesting to see there's more than one MS6 with this problem.
 
1 - 20 of 26 Posts
Top