Perplexed by electrical issue
 

Hello all. I have had some issues with my 2011 Hyundai Genesis recently that has me perplexed. I have replaced the battery and had the car be completely dead. But I can test the battery and the battery is good and has a charge. I can jump the battery and can get the car to start.

I have taken the car to a mechanic recently to have a draw test done and verify that I didn't have a bad alternator. Everything came back good. But that night, same issue. Car was completely dead. Doors won't even lock.

This seems very similar to when cars had a manual shutoff switch where the car could almost be completely disabled. I was wondering if there was anything similar that could behave that way or does anyone have any other recommendations?

Thanks,
Bryan

From what you are telling us, You jumped the present battery and everything worked and the vehicle would start. If this is correct,, possibly one of a few things.
!. Your battery could be defective
2. The cables have a poor connection at THE BATTERY.
3.. Something is staying on and draining the battery. That is easily checked with voltage drop at the fuses. There is a procedure where certain conditions need to be set up to verify all the modules are going into sleep mode after the key is turned off. This can take around 45 minutes for all modules to go into sleep mode.
Sometimes,,,, something left on can do this too. Check the rear wiper if it has one , for being stuck where it can't park itself and shut off.
Also , if the remote is left in the vehicle when parked, it tells the network don't go to sleep, be ready to start.

The jump by passes your battery and provides the power for the starter to work.

Really appreciate your response. I went out and tinkered with it. We tried to jump it. Didn't work. In fact when we tried to jump it the horn honked but the cluster remained dark, nothing came on and we tried some other things. When I went to go pull the battery and put the key in the trunk the doors that were open to the cabin of the car started to "ding". So I tried to start the car and it started. We ran it for five mins, drove it around the block and turned it off.

I started to think. The battery wasn't dead. There was something like a shut off switch that was prohibiting the driver from getting anything to work. And if the mechanic was right last week that there was no draw, the battery was good, etc. then what could be there causing this issue that impacts the car starting, the doors from locking/unlocking and what might see a key being inserted as a way to reactivate?

Then I started to think about the aftermarket remote starter. I called the shop that did the install and they asked for us to bring it over. When they pressed the remote start nothing happened but the lights blinked and he said that was an error code. He went back and figured out that the code was that the starter was put into "valet mode". He couldn't verify the other behaviors of if a car was in valet mode would it act "dead". And in taking the vehicle to him the car just "shut off" as we were driving it.

So we got it taken out of valet mode and so far so good. We also know what could have put it into valet mode which was the dead battery/new battery. My son thought all of the issues were interrelated but once we were able to kind of establish that timeline we think that we may have a fix.

Thanks again!

Thanks for the update.