I have an 07 Santa Fe. Yesterday, I drove this car to work and drove it throughout the day. No problems with starting or any power issues. After I came home late afternoon the car sat for several hours.

Last night, I went to start the car to leave the house and as I was turning the key the car just went completely dark and no power. Nothing. The door locks didn't work, no lights on the dashboard, just completely dead.

This morning, I looked at the battery and everything appeared normal. The cables on the battery were tight, no corrosion, everything looked ok. I opened the fuse box, by the battery, and popped the fuse "START" and put it back in and suddenly I got power. The car started and I had power again.

What, possibly, happened to the car? How did the car lose power? Is this an early sign of something failing?

 

Hi:
That sounds similar to a problem with my 05 Santa Fe a few months ago.
https://www.hyundaiforum.com/forum/h...steries-20415/
No solution yet, but it has happened twice. The first time I described in that thread. The second time it was very brief: reseating the negative battery post connector brought the power back. It could be a bad ground connection somewhere. Or you might have solved it. If it happens again, I'll try that Start fuse.

 

Just a follow up. The car continues to lose power randomly. The "start" fuse in the fuse box near the battery, seems to give the car power. After I lose power, I will disconnect it then reconnect it and the car has power again. I am not sure what relationship it has but seems to give the car power.

I don't know yet if this issue is battery, alternator, or something else. I will bring it in to my repair guy to look at it.