I have a 92 Honda civic ex the car runs fantastic but in the last couple of days my battery has been draining. I disconnect the battery and the car dyed I heard that this means that it is the alternator could it be?
Also I find that I am burning my headlights out fast. They are sealed, there is no moisture or cracks they are single bulbs. It seems that I am burning running & high beams alot, like every 2nd 3rd month I am changing them. Any advice on this would be appreciated. Thank you in advance.
Have you ever had the red warning lamp with the battery icon (= actually the charging system warning lamp, typically indicating a faulty alternator) come on?
1- Never disconnect the battery on a vehicle with the engine running.
2- You may have neglected to squeeze the tiny triangles on the headlight connectors, then yanked the connector off. You'll have to repair the 'grip' that the brass lugs are supposed to exert on the lamp's prongs. Since they have overheated now, replacement of the whole connector is probably required. When the connectors get hot they contribute to the lamp burning out since they stop conducting heat (away from the lamp) and start generating it.
3- If overvoltage was the cause of your headlamps burning out, your radio would be toast too.
4- Test your dash warning lights per the owner's manual to be sure all are working.
Elle is on the right track here; Curly is on glue.
Definitely sounds like an alternator issue. Your first test of disconnecting the battery was the right one; you don't want to run that way for very long, but it's still a valid way to isolate battery from alt problems.
Your best bet is probably to go to a shop that can properly test and repair (if necessary) your alternator, but if you want to diagnose it yourself, the first thing you're going to need is a multimeter, preferably digital. Most auto-parts stores should have basic ones starting at around $15-$20. With that, you can perform some of the tests in this document:
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(note that they show Fluke meters, since this is Fluke's document, but any meter with the same functions will do the job). Check for overvoltage first - connect the meter across the battery posts and rev the engine; watch that it doesn't go above 15 volts DC. Turn all the accessories on (rear defrost, lights, fan, etc.) and watch the voltage. In normal conditions, it should be around 13V at idle with everything off, down to
12-12.5 with accessories on, and around 14.5V when revved up.
If it is in fact overvoltage that's killing your lights (and despite Curly's assertion, a slight overvoltage can easily shorten the lifespan of your headlights without killing the radio), it's possible that it's also damaged your battery, and that's not holding a full charge anymore. If you find the reading too high, have your battery tested as well (any auto shop should do this for free).
I agree with Curly; the risks of disconnecting the battery with the engine running are terrible. With a good alternator it is a little risky, with one that has bad diodes (you do suspect the alternator is bad, right - why else do the test?) you seriously risk huge spikes to all the electronics in the car. It's not a big deal with a car made before about 1970, but don't *ever* do it with a modern car. It never was a very good test, either; alternators with bad diodes would still run the car but would fail to keep up with loads like driving at night with the heater fan on.
The way to determine whether the alternator is working is with tests as Elle describes. Personally, I also check for AC voltage with a digital voltmeter under the same test conditions. Good diodes will produce less than 0.1 volt AC, while bad diodes will produce 1/2 volt AC or more. The last bad alternator I've seen (in a friend's Taurus) had two bad phases and the AC voltage was 1.7 volts! An oscilloscope is even more definitive, as the waveform of a bad phase is unmistakable, but in practice I've never seen high AC voltage from an alternator that didn't have bad diodes. Alternators with bad diodes will also fail Elle's test #3.
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