YR - 2009

Been dealing with slow parasitic drain for a while now and i really need help!

- beginning of my problem: left light inside and drain the battery, i charged my battery at 2A (slow charge) and after a couple of day - it fully charged, around 13.3V
- after 4-5 days of not driving, battery again was measuring 9-8V, i thought my problem was the Positive clamp was not clamp tight (which i didn't pay attention initially)
- after i corrected the clamp - i was still having problem with my battery draining down to 9-8V after 4-5 days of not driving (from full charge of 13.3V)

- i installed the new battery and 1 month no problem - sometimes the car is not driven for 5days and it had no problem starting (i didn't measure the voltage anymore)
- Less than 2 months later i have problem with battery drain again after not driving for 4-5 days
- i finally decided to be more methodical:
- Tuesday after driving, open the hood, lock the doors and wait 2hours, battery voltage = 12.65V
- Wednesday (not driving the car), open the hood and lock the doors and wait 2hours, battery voltage = 12.20V
- i will repeat the process again tomorrow (if necessary)

- other plan is to measure the current (should be 50mA or less) and remove fuse one at a time - this requires more work since i need to make sure the computer is sleeping and all the doors in lock position (learnt from Youtube)

- other plan is to just remove most of the fuses and check if there is less voltage drop after 1 or 2 days

Anyone have better idea what cause my slow battery drain from 12.6 to 8V after not driving for 4 days!!!

Note: i don't have any extra accessories in the car like charger or dashcam.

 

Before doing any testing, you should have the battery *load tested.
If the battery is not in *good health your testing may result in inconclusive, or you may think you found the problem only to have it continue.

 

update:
I placed a clamp a (thick) wire between the Battery Negative and Car Negative battery clamp
Turn off everything and close all the doors except the front, but push in the lock for front door - need access to fuse box
after 1hour of idle disconnect one end of the clamp wire and place my DC Amp meter in between w/o breaking voltage connection
my current was measuring 400+ mA
- start removing fuses one at a time
- removed fuse # 12 for ROOM (Audio system, overhead lights) - current drop to less than 10mA
- return fuse # 12and disconnected connectors for both front overhead light and mid overhead light - current still current at ~400mA
- i didn't remove the luggage light yet
- I don't have the skill/tools to remove my audio system!

Another Update:
- w/o this fuse, i can't start the car, can't turn the engine on, no lights on the front console!
- how do i even start to look for the problem!!!

 

https://www.mazdaforum.com/forum/maz...c-drain-39452/

from the thread above - looks like another member mentioned that the cause of the parasitic drain was the Bluetooth module
my Bluetooth stops working 5+ yrs ago and my parasitic drain problem started just last year, but best to first fix known problem
will someone be able to help me locate the Bluetooth module

 

Very common issue not exclusive to Mazda, Hands free telephone module is behind glove compartment.

 

Update: fix the problem😎
- it's the Bluetooth module
- after i disconnect the cable attached to the module, turn off everything, locked all doors and wait 30mins
- my current went from ~300mA to 30 - 45mA


please remove video if not allowed - just a video of the current draw

- location of the Bluetooth module is on the right side behind the glove box compartment



thanks to everyone😃

 

Chris you did a fantastic job to locate and find your power drain. Complient's to your skills as a DIY using a Digital volt ohm meter and knowing how to find the battery power drain. I would say it has been 1.5 decades since I have actual read a member that is not a service technician on any forum perform the tedious task finding power drain especially from a vehicle that has several power systems that are constantly using the battery power.
job well done !!

 

thanks and thanks to this forum
- the Bluetooth module idea came from another forum member that provided updated info on his parasitic drain problem