2006 Mazda 6 Electrical Issue - Battery Test Good
 

New to the forum. I have a 2006 Mazda 6 that would not crank a few days ago. First thought was dead battery. While jumping it finally cranked but I had the feeling it wasn't the battery. Went straight to Advanced Auto and tested battery. Battery tested good. Five days later, same thing but this time had to have it towed. As key is put in the ignition the dash lights start blinking, gauges bounce but absolutely not power. No headlights, no horn etc.... Mechanic checked ground and to frame and says it's good. They could not get it to do anything. He only offered that it might be the key/security problem. Car has 201K miles so do not want to spend a fortune. Any help? similar symptoms ? relay problems?

Thanks

JB

My Dec 2018 Mazda 6, manual/petrol is now on its 3rd battery! Now flat again and waiting for the RAC to come to my help once more. Have read the trials and tribulations of others with the same problem. Has this been officially diagnosed and sorted yet by Mazda? Am not aware of any recalls.

After removing battery cables, letting sit over night and replacing battery in key fob. I have power to lights and inside dash but still won't crank. Used a super heavy duty jumper to get cranked. Took to Keefer Mazda. Bad Battery. $349 later. Lesson learned. Wish I would tried that myself. Still not convinced I don't have another issue, but only time will tell.

Well, we made it a month. Mazda 6 did the exact same thing. No power, door will not even lock. Has anyone experienced a security fault that may cause this?

$349 for a battery replacement. Ouch.
It takes very little power to lock the doors. You should be able to lock and unlock them from inside the car without the fob. How’s the manually switched stuff, like interior lighting doing? Head and brake lights? I’m suspecting something intermittent. Could be a loose ground or any number of places either in ground or power circuits. Do you have a voltmeter you can probe around with to see where the drop is occurring?
You’ve got some sleuthing ahead of you. Hey, something to do while social distancing.

99.95% sure I have figured it out. Bad ground. Took jumper cable black and ran from negative battery terminal to a mount that has a ground connected. Immediately get lights and audio back on dash. Security light stops blinking and car cranks right up. Removed cable, car looses everything after trying to start. Reconnected cable, fires up every time. Now, do I just run another cable from negative battery cable to this mount or try to trace down the problem? I have read that there are multiple ground connections. I have no shop or lift so I'm guessing I will run temporary cable til I can find a local shop. Thanks for the response! I have to give a great deal of credit to scannerdanner on youtube. https://www.youtube.com/channel/UCrf...oy4alB2WXJCIqA

Good on you, mate! If it were me, it’d run a redundant ground from the battery to a solid chassis ground point, and another from either the battery or the chassis ground to the body frame. You can get a battery ground cable with the connector easier than trying to source a #2 or #4 copper wire and putting on some large crimp connectors. They make battery connector cables with multiple wire leads and lugs. Sounds like you pretty much got it licked. :)