My 2003 Hyundai Elantra was running just fine. Tonight, I was sitting in my car with the engine off listening to the radio for a few minutes. When I turned the key to the start position, there was a click and all lights turned off. Then, silence. After a bit, the lights would come back on normally, until I turned the key to "start" again.
Internet searches suggested that the problem could be a bad/corroded connection between the battery and a battery cable. So, I ran tests with a volt meter:
- Testing the voltage across the battery terminals consistently read about 12 volts, regardless of what I did.
- Touching the voltmeter probes to exposed parts of the battery cables produced the following results:
- When the lights were working normally, the voltage was about 14 (by my old defective multimeter; I don't have a reading on this from my new meter).
- Opening the driver door caused the voltage to drop to nearly zero, then recover to around 1.5.
- Attempting to start the car with the lights working normally caused the voltage to drop to nearly 0, then recover to around 1.5. Further attempts to start the car had no effect until the lights started working again.
Because several sources suggested a bad connection between the battery cables and the terminals, I disconnected and inspected them. This battery is nearly new. Upon inspection, I found no evidence of corrosion or a loose connection, and the terminal grease was still intact.
I'm mystified as to how such a problem could crop suddenly with no prior warning. Any ideas as to what I should try?
By the way, my symptoms are basically the same as this question, but as the answers there don't appear to solve my problem, I'm asking my own question.
I switched multimeters after determining that the one I previously used was giving incorrect readings, and I've edited my post with updated numbers.