Car loses all electrical on start up and then returns

Question

My car (2011 Honda Fit) has lost all electrical power a few times in the past while. For example, I was at a gas station, and when I got back in and turned the key, it had power for a second, and then all the electrical was gone ...the lights on dash, clock on radio, etc. were all not "on".

I thought maybe the battery connection had come loose somehow, so I opened the hood, but everything was connected... but I fiddled with the battery connections anyway, got back in, and it started up fine.

It happened twice since then. It is only on startup, that is, I have not had any problems while driving. And other than the sudden loss of electrical on startup, I don't have any other issues.

I did clean the negative battery terminal, but I left the positive alone since it was clean. When I tried to start it up again after that there was again no electricity (maybe some of the dash lights were a tiny bit dim, hard to tell in bright daylight). I again just fiddled with the battery connections and it eventually had electrical again, but it seemed to take longer/more fiddling this time. But I'm not really sure the fiddling is "fixing" it, whatever it is it seems random.

This is similar to this question 45311, but no final answer there.

Does this sound like a bad battery connection, like something with the wires? Or could it be something else like a bad alternator, bad battery, or a bad relay? I am not sure if any of those would allow the electrical comes back on??

Any thoughts?

Answer 1

This sounds like a bad ignition switch. Has your ignition key ever felt hot after you turn off the car? This was an early sign of failure.

Start your car and remain parked. Now with the engine running, start playing with the ignition switch. Don't turn it, but tilt the key up, force it down, push it in and out, slightly turn the key one way or the other without actually going to Start of Off.

Does the engine quit or stumble? If so, it's a bad ignition switch. If you have a big heavy bunch of keys that dangles and swings from the ignition, this tends to wear out the ignition switch.

Answer 2

A voltmeter and a schematic* can locate the problem somewhat readily, if the problem is persistent and not intermittent. A friend had a similar intermittent situation and I recommended "permanently" wiring-in light bulbs (or LEDs with resistors) into the circuit(s) so when the failure occurred at an inconvenient time, it could easily be seen where the problem lied.

That said, I thought I had a bad connection issue once, but it was actually a battery that intermittently failed internally to where it would only supply a small amount of voltage, not enough to power things in the car, let alone start the engine. The battery was only months old.

*Some public libraries have wiring schematics for automobiles.