Hyundai Forums banner

1 - 16 of 16 Posts

·
Registered
Joined
·
3 Posts
Discussion Starter #1
Turn the key on, dash lights turn on. Turn the key to start, all lights turn off, everything is dead. Battery is good. Any ideas?
 

·
Registered
Joined
·
131 Posts
We've found issues with the negative battery connection at body.
Follow the black cable from battery. See where it is connected at vehicle. Hyundai, in their infinite wisdom, made the connection on top of the body paint.
To repair, remove bolt that secures cable to body, use sandpaper to remove paint at connection, re-attach cable and spray over connection with paint.
 

·
Registered
Joined
·
403 Posts
Turn the key on, dash lights turn on. Turn the key to start, all lights turn off, everything is dead. Battery is good. Any ideas?
What does "Battery is good" mean? Did you do a load test, was it recently replaced... etc? Just because you're getting 12+v at the terminals doesn't mean you have the amps and remaining juice to actually start the car. On my original Hyundai battery which I replaced a few months ago, everything was great until one day one of the cells decided to start going. Voltage was good but you test it for load and it would fail. Measure voltage when you're trying to turn over . Ground and starter come to mind too along with Neutral Switch at the transmission. Can you try starting in Neutral?
 

·
Registered
Joined
·
1,733 Posts
When trying to start, measure the voltage between the negative post of the battery and the engine. It should be near zero, but if you have a bad ground you will measure voltage. Anything above ~1.0VDC indicates a bad ground. Presumption here is that the new battery is good.
 

·
Registered
Drives : Nissan NV200 Flies : Rans S6ES
Joined
·
15,313 Posts
Turn the key to start, all lights turn off, everything is dead.
These are symptoms of a high resistance, usually caused by a corroded/loose connection. As flemmons suggested, voltage drop testing is the way you diagnose the cause. I think it's more likely to be a body ground issue though, rather than the engine ground. You'd want to measure the voltage between the battery neg post and clean metal on the car body. The lower the voltage the better and >1V is defo a problem.

You can also get high resistance on the positive side of the circuit too, so if the grounds check out OK measure the voltage between the battery positive post and the stud where the main power cable connects to the engine bay fusebox...see below. You want to perform these test while the fault is present, so while everything is dead.

 

Attachments

·
Registered
Joined
·
184 Posts
Two other suggestions as I don't know the year, check that the car is in Park as Sonata's have issues with the shifter. Second, check the brake switch under the pedal. Both of these items have been recalled.
 

·
Registered
Joined
·
4,471 Posts
Turn the key on, dash lights turn on. Turn the key to start, all lights turn off, everything is dead. Battery is good. Any ideas?
Two other suggestions as I don't know the year, check that the car is in Park as Sonata's have issues with the shifter. Second, check the brake switch under the pedal. Both of these items have been recalled.
OP's original statement tends to rule out those suggestions regardless of year. More indicative of what AUTOSPARK and Login:LordByron are indicating. I would also have my battery tested for sure (or have it hooked up to a jump) to make sure I didn't get a battery with a bad cell.
 

·
Registered
Joined
·
153 Posts
What about it?
If the battery is new I would think it was replaced because of a previous battery not operating correctly. If the alternator isn't charging the battery properly it won't let the car start. Being a new battery there should be enough juice in the battery to turn the lights on in the car but not turn over the engine. My first idea would be to try and boost the car with jumper cables and if it starts I would 100% say the alternator if not then void my theory lol.

Sent from my SM-G935W8 using Tapatalk
 

·
Registered
Drives : Nissan NV200 Flies : Rans S6ES
Joined
·
15,313 Posts
An alternator fault doesn't really fit the described symptoms. Not when the OP has measured 12+ Volts in the battery. That's enough juice to power the ignition lights yet...."all lights turn off, everything is dead".
 
1 - 16 of 16 Posts
Top