So I think my alternator is bad and want to replace it but want to be sure first ('99 EX). Here is what happened:

I've been hearing a intermittent wining noise in my car, which I thought was some type of pulley. It went away but today it came back. My wife and I went to the park this evening, and everything seemed fine with the car. Then we got back to the parking lot and I started the car and I could tell the battery was low from listening to the car start. Then we got back home to our apartment parking lot and I tried turning it off and cranking it another time or two, and after that the battery was so low it wouldn't start. So my wife helped me clutch start it. After I clutched started it I pulled it around the parking lot a little bit. As long as I stayed on the gas it was fine, but if I let off for a minute the car would stop. I clutched started it again and whenever I would press the gas the headlights would get bright, but if I let off and let it idle, they would get dimmer and dimmer until it stopped. So I parked the car, still running, when I came back out it had stopped again. Measured the battery voltage, and no surprise it was down to 10 volts.

The battery is less than 6 months old so I don't think it's that. I heard one test for an alternator is to disconnect the battery while the car is running and it should keep running being powered by the alternator. Well in this case, even if my battery was dead, after I clutch started it it still should of kept running if the alternator is good right? Not sure what else I can do here as the car won't crank now. I can replace the alternator and belt as I have all the tools and time to do so this weekend, but want to make sure this is what's wrong first.

Let me know what you guys think. Thanks!

 

Since it's a 1999 Civic, check your fuse 15 first. But other than that, sounds like the alternator is bad.

Don't ever do the disconnect the battery test on a modern car. Measuring the battery voltage with the engine running tells you the same thing.

 

Last night I checked fuse 15 and it was intact, also did a continuity test between the alternator post and the positive terminal of the battery, no problems there. Lastly I disconnected the negative terminal and checked the current draw when the car was off, almost none, low milliamps. I picked up a rebuilt alternator and belt this morning from O'reilly.

I have an EX, so to take off the alternator belt I need to remove both the power steering and AC compressors belts, correct? What other things do I need to move to lift the alternator out from the top? The brake master cylinder looked like it might get in the way. I wanted to measure the voltage when the car was one but it died so, maybe I'll try to clutch start it today again and measure the voltage before the engine kills.

 

I think if you jack up the car until the left front wheel hangs free (so the axle is all the way down) it will come out the bottom. It doesn't work to drive up on ramps since the wheel stays up then.

 

So I was able to drop out the old alternator from the bottom, got the new one in, put the bottom bolt in, but then problems.

It's like impossible to get the top lock bolt back into the threaded hole on the alternator. I'm starting doubt whether the hole was threaded correctly. On the old alternator you can also thread it in on the back, on the new one I tried this and it only goes in a couple turns and then feels like it's the wrong size. I tried putting the screw in outside of that little cutout but I can't seem to get it in. Gave up for tonight but tomorrow I think I'm going to pull the alternator back out and verify that the hole is ok.

Any suggestions?

 

Sounds like the hole is bad.

To get the top bolt in, you will need to loosen the bolt at the engine holding the curved slotted piece so it can move a little and line up with the bolt hole in the alternator. Tighten that bolt after setting the belt tension and tightening the top alternator bolt.

 

Alright so I finished. The hole was actually ok, it was just really hard to the screw in. I loosened the bracket like you said which helped (which I could really only get at the bolt from under the car with enough leverage). That was really the hardest part about this whole thing. The only other thing that went wrong is that I kind of rounded out the bolt for the idler pulley so I couldn't get the AC belt off so I just cut it since my AC isn't working right now anyways. So when I troubleshoot that later I'll fix it. I was using a 12 point wrnech and like a idiot was turning it the wrong way at first, it was already rounded pretty good though from whoever last took it off. My friend recommended using a 6 point closed wrench, so maybe I'll try that later.

Car now runs and the battery is charging up just fine. Thanks for the tips.

 

Ok, so I had another issue come up. First off, after jumping my car and replacing the alternator the other day, when I measured the voltage on the battery after starting it, it showed around 14.5 V I believe.

Today, I'm on the way to work, and all of a sudden over half way through my trip, the ABS and SRS lights begin turning on and off intermintantly with no pattern. I've seen this happen before, and I fixed it last time by jiggling my positive side battery wires. When I was pulling into work, it was still doing it, and then all of a sudden I smelled kind of a burning rubber smell (which I smelled last week the day my alternator went out) and a loud belt squeal. So I parked and turned off the car. I tried to crank it then, and everything came on including the fans and my radio, but the car wouldn't even try to crank at all. So I opened the hood and jiggled the wires like before. Went back and cranked it and it started with no problems.

During lunch I went out to my car with a voltmeter and started the car and let it idle. I measured the voltage and it was about around 12.5 V (closer to 12 when I turned a bunch of things on in the car)! However, it still seems to be charging the battery some, as the battery doesn't loose it's charge after driving around with my fans, radio and headlights on (keep its charge).

So I'm not sure what's going on here, what are some things I could check. First of all, I was thinking about cleaning all the wires going to the positive battery side, as jiggling them seemed to fix the problem with the car not cranking, and they are all nasty and black. I was also going to try to tighten the belt, as it seems like it might be a little loose (which would explain the squealing this morning and maybe the burning rubber smell??). I was thinking maybe if my battery post was loose it was loading my alternator a lot, and if the belt isn't tight enough maybe it's making it slip more. Also, the lights are no longer flashing after I jiggled the harness.

Not really sure what to do other than pullin git out and taking it back to O'reilly for them to test the alternator alone. That's a last resort though. If anyone has any ideas let me know.

 

Having to jiggle the terminals means you need to take them off, clean the inside of the terminal and the battery post, and re-attach securely. Loosen the nut fully so the terminal slides all the way down the battery post. There should be some post showing above the top edge of the terminal. Then tighten the nut.

 

Yeah I was going to try this after work. Do you think that perhaps loose battery terminal wires could affect the control of the voltage regulator telling the alternator to output a lower voltage?