Kia Optima Forums banner
1 - 5 of 5 Posts

·
Registered
Joined
·
1 Posts
Discussion Starter · #1 ·
My optima hybrid has about 130k miles on it and works perfectly except for this one odd issue that I nor the dealer can figure out. Every so ofter (about once a month), the car will for no reason act as if the 12v is totally dead. However, I do not believe that this is the case. My jumper box has a volt meter on it and before I energize the jumper cables I read the voltage from the battery and it is always around 12.4 to 12.6 volts. However, whenever I power on the jumper box, the car instantly jumps to life and blares the alarm. Then it behaves normally as if nothing has happened. No lights on the dash, no errors from the OBD port as stated by the dealer. Does anyone have any ideas? The dealer doesn't seem to believe me (they think I am some kind of ditz) and just keeps wanting to charge me $30 to replace the key fob battery. They say nothing is wrong with the car, the main pack, or the 12 volt. Has anyone experienced such an issue? Could it be a drain protection feature that is automatically activating because the car thinks there is an abnormal draw somewhere?
 

·
Registered
2012 Kia Optima 2012 Kia Optima LX
Joined
·
37 Posts
You don't say whether your current battery is original or not. If it is more than five years old, replace it.
 

·
Registered
Joined
·
3 Posts
You can replace the key fob battery for a couple bucks. Just pry it open with a knife and swap out the battery. It's a generic CR 2032. If you need to replace the 12 volt battery in the trunk it's a special type called an AGM battery. The last I knew it was only available from the dealer and costs almost $400. You can change it yourself in less than 5 minutes.
 

·
Registered
Joined
·
1 Posts
I've had similar issues with my 2012 optima 2.0T. I managed to track it to the main fuse off the positive terminal of battery, inside the terminal post enclosure thing. Turns out you can over tighten bolts/nuts, and "service technicians" happen to be really good at it. After a trip to the shop for a new alternator the tech cranked down the nut (inside enclosure) that's threaded onto the vertical rod/bracket that sits on the blind side of the battery flexing the entire main fuse. The fuse is housed mostly in a sort of high temperature plastic heatsink. Embedded in said plastic, are the blades of the fuse. The flexion caused the internal (hidden) part of the blade to crack in my particular case. Internal arcing had burnt some of the plastic causing it to bubble out of some parts of the fuse. The smell was pretty gnarly in the engine compartment, and the cab from the ventilation system (when not recirculating.) The arcing damaged the battery, and seemed to confuse the guys at the shop enough that they replaced the alternator again, and not the fuse. Getting me another tow home, and another trip to the shop for a new fuse and a few days off the road. Needless to say, they cracked the new fuse.

It can be tricky to spot if you're not smelling the plastic burning, but if you look for any crispy bubbly secretions on the fuse, also the fuse window might have some soot or Burns inside but the visible part of the fuse intact; you might just find your answer to your problem. The partial contact can throw any electrical tests out the window. I'm not sure if the battery set up is the same for the hybrid model, but if it is the fuse would be worth checking out.
XOXO,
Dingle, Barry
 

·
Registered
2013 Ebony SXL Turbo: Original Everything @ about 193K with Drag wheels.
Joined
·
416 Posts
I read alot about that 'Gorilla Over Tightening Syndrome', not just Kias either, haha.

Thanks for sharing.
 
1 - 5 of 5 Posts
Top