I have a 2012 Mazda 5 Touring with approximately 52k miles on it, and started having a strange issue yesterday.
It started fine and drove fine, but when I went to get back into it after being in a store for 30 minutes, it was completely dead. The keyless entry didn't work, and once I manually unlocked the door, no lights came on and the car would not start. After having the battery checked out, it was found to be in perfect working order.
After 45 minutes of sitting the car started without issue and was fine the rest of the day.
This morning, same thing- ran fine for a while, in fact was fine for several errands. Went back out later to do more running around, got in, started it, then it died while backing out of the garage. No power of any kind again. Still no power after several hours today.

Anyone with any insight/guidance would be greatly appreciated.

 

Have you pulled the battery terminals and ensured they’re clean and tight? I had something similar happen on an old ranger. it would crap out and I had to go jiggle the terminal clamp. Ended up having to replace the clamps because they were old and worn out and couldn’t actually maintain a tight grip on the battery posts. Also check to make sure your grounds are good. Maybe have a corroded wire and that explains your intermittent symptoms. turn it to on, or turn on the headlights or something then start bending/jiggling cables to see if something turns back on.

 

I have no warranty, I own my car and I’m not exactly equipped with the kind of money I imagine it might cost me to take it to the dealer. So...

Does anyone have any idea what could cause these issues? What kind of prices can I be charged by the dealer? Is it possible to have electrical issues looked at by a regular Speed Test mechanic?