Bad alternator. How do I check

[chicagoavenger]

Hey guys I think my alternator is shot. Its not charging the battery and if I charge the battery for awhile and run it, it runs for awhile then starts to loose charge then the car just starts kicking and bucking then dies. If I jump it and let it sit charging for a bit, it will run then start dying after a bit. I was wondering what other ways to check if the alternator is bad. I dont wanna take something out that's working. I'm 98% sure it's that but just wanna be 100% thanks.

 

[dirk3]

Alternator is shot, make sure your power steering pump isn't leaking. If it is fix that when you replace the alternator... If you want to test the alternator just put a volt meter to the battery with the car running and check the volts should be around 14.4 or so.. but if it reads less than 12v your alternator is bad. You can also check your alternator fuse...

 

[chicagoavenger]

I just broke the damn fuse!! Can I get one at the autostore? It will have to wait till tommorow. I'll post up after I get the fuse and do a volt test like you suggested. thanks

 

[dirk3]

You should'nt have any problems finding one at an autoparts store.. just bring in the old one thats what I do...

 

[ZachM31]

yeah a fuse isn't very hard to find, i blew my alternator fuse and went to a local auto store and got 2 of them, it was $8.63 total i believe. it does sound like your alternator though, i was going to say it could be a bad cell in your battery, but you said it would buck and die, so yeah your engine isnt getting any voltage to fire the spark plug!

 

[chicagoavenger]

Thanks, I'm going to get the alternator tommorow, thanks for the help again. Much appreciated.

 

[versatilx1]

holy crap i had the same problem but to the excellent feedback on this i found out my fuse was gone too. good looking out

 

[chicagoavenger]

Got a new alternator and the voltage is reading low again. Even got a new battery.. now what? is it a bad alternator? I have been reading some old post about new alternators going bad. My new battery when the car is off is 12.6V. is that right?

 

[dalepmay]

Easy way to check alternator in any car:
1. Start engine.
2. Turn all lights, radio, windshield wipers, everything possible.
3. With everything going, unplug the positive wire from the battery.

If the alternator is good, everything will stay running. If the car dies, or anything stops working, your alternator is not putting out enough power.

 

[chicagoavenger]

I was just about to ask that. I just did that and with no acc on if I pull the positive terminal off It dies, I dont undersdtand I just got a new alternator!!!

 

[roffles]

Easy way to check alternator in any car:
1. Start engine.
2. Turn all lights, radio, windshield wipers, everything possible.
3. With everything going, unplug the positive wire from the battery.

If the alternator is good, everything will stay running. If the car dies, or anything stops working, your alternator is not putting out enough power.

Do not ever remove your battery cable with the car running, you have a great chance of frying your ecu.

 

[dalepmay]

Do not ever remove your battery cable with the car running, you have a great chance of frying your ecu.

Actually, doing this does absolutely nothing to your ECU. If your alternator is good, everything keeps going just fine, including your ECU. If your alternator is bad, everything shuts off, just as if you turned your car off.

 

[SkyLineGtR-R34]

autozone can check the alternator

 

[talonkev]

Just take the car to an autoparts store and have them test it. Most places like advance will do it for free. NEVER take the positive terminal off of a battery while the car is running, that is an old school trick. It can cause a voltage spike and blow all your fuses or even ECU as stated above.

 

[chicagoavenger]

I took it in ad the new alternator I got was bad. Got a new one got it tested before I left and she is up and runig now. Thanks for the help everyone

 

[94greentsi]

This is for everyones info. My alternator died about a month ago. Here are the problems that were associated with it:

1. Lights in my console were coming on (not all of the way, just dim). Which I thought was strange...kind of scared me actually. Some of them were my coolant light, my charging system light(obviously) and my ABS light would kick on and off.

2. Regarding the ABS light. When I would depress the brake, I would get a really strange pedal feel, and if I was holding on to the shifter, I would get a weird vibration in the shifter at the same time.

3. I stupidly decided to race a guy later on the next day , not thinking about the lights on the dash etc....I beat him, but when I slowed down, my motor started to do the crazy idle surge. I have read about the idle surge problem and the fixes associated, so I didn't even think that it had anything to do with my charging system. Well I was wrong.

4. I parked the car after my race, and 10 min later I had to go out again, and the car wouldn't start. I got the car boosted from my roommate, thankfully. My roommates dad is a mechanic and an electrician, so he was able to diagnose the problem

5. I drove over to my roommates uncles house, and the car died while I was pulling up the house. The motor seemed like it was missing spark and had no power.

6. So what we did was hook another battery up to the car, basically like a boost. I kept my battery in the car. Well, the car started right up, but there were still all of those lights on my dash that I mentioned earlier. We disconnected the helper battery, and checked my battery with a voltmeter. Sure enough, it was up at around 13 volts, and was dropping by increments of around .25 to .5 per every 2-3 seconds.

7. We looked at some other possibilities, but deduced that it was the alternator, so I went to Partsource (like autozone for you American dudes) and picked up a new one. I installed it the next day, and while I installed it I charged my battery really good with a nice slow charge. If you have every changed one, its not extremely difficult, but the manual (which I didn't have at the time) would have been really helpful

8. I fired up the car, with the new alternator and belt, and she purred like a kitten, and all of the crazy lights went off on my dash which was a big relief to me. My idle surge has never come back either, which made me even more ecstatic.

So friends I thought I would post my experience, so that if anyone of my fellow dsmers have the symptoms that I had with my car, it may be your alternator, but check the whole charging system out first, because replacing unnecessary parts sucks.

forever

 

[vrooman]

Alternator is shot, make sure your power steering pump isn't leaking. If it is fix that when you replace the alternator... If you want to test the alternator just put a volt meter to the battery with the car running and check the volts should be around 14.4 or so.. but if it reads less than 12v your alternator is bad. You can also check your alternator fuse...

i am having problem with 1992 lasers alternator where is alternator fuse located

 

[motomattx]

i am having problem with 1992 lasers alternator where is alternator fuse located

In the outside fuse box under the hood, it is one of the large fuses.