My hyundai elantra just keep dying. So i thought it was the battery. I bought a new one.. all of sudden it dies again.. so I got the alternator checked.. it's not the alternator or the battery. Just out of nowhere while I am on the road.. the rpm needle just starts going crazy.. then all the lights starts getting dim.. then it just stops.. What do you think is wrong my car?

sound like the alter belt or the alternotor itself needs to be replace to go the cheap way first i would have my battery tested and to check the alter yourself do this easy test start the car with the car running remove the postive battery cable off the battery if the car stay running then the altern is good if it shut down you need a new alter good luck

After connecting battery, try using key in drivers door to lock, and /or unlock. Try passenger if that doesn't work, as well as valet key if it came with one.

Yes, it is likely an alternator since the battery light goes on when the alternator is not charging.

Good luck on this one.

If you have replaced the alternator and the battery has been checked and showed to be in good working condition then the only thing left is either a bad fusable link or cable (negative or psitive) going from battery to engine. You should inspect these cables and there connections. Corrosion on these connections can cause these problems. You also mention that the alternator will not keep car running. It should when you disconnect the negative battery cable while the engine is running.If all connections and cables are good and you haven't replaced alternator then you should do so.

crank sensor will cause similar stalling issues. You may have got a bad alternator, if the battery light is on after you jump it, probably needs a new, new alternator. make sure all your connections are tight and plugged in, both on battery and alternator.

The odds are the alternator is the problem again. I've installed brand new alternators in the shop that turned out bad. The battery barely had enough juice the crank the car and get it running. Then, the battery was the only thing keeping the engine running with the spark plug until the battery drain completely dead.

If the alternator was working normally, the alternator would have kept the energy up and keep the spark plugs going without the battery's help.

Basically, the battery's job is to start the engine only and the alternator's job is to keep the battery charged and supply energy for the car's needs.

At first I would suspect the alternator isn't charging the battery -- Now that you mention 'SMOKE'.. Take/Tow your vehicle to an authorized Hyundai dealership and pay the diagnostic fee... they will tell you exactly what the problem is and the cost of parts/labor to fix it... at least this way you'll know what the problem is and what's required to fix it.

try to check ignition switch or replace it

clean the cables, if still not working, every time you finished using the car disconnected the negative cable from the battery. and then connected it back when about to use it again.

What was the original problem before you replaced the alternator?