2nd Generation Specific (1986-1992) 1986-1992 Discussion including performance modifications and technical support sections.

alternator going bad?????

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Old Feb 14, 2006 | 09:13 PM
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alternator going bad?????

ok so i drive to school and everythings fine. After about 2 hours i get in my car and when i start it the voltemeter needle like, bounces (kind of goes up and down really fast all over the gauge) and settles at 14ish. As i drive around, i noticed that when i hit the brakes, my cd player (stock) will skip, everytime i hit the brakes. And sometimes when i turn, my power steering, like, goes out, and it becomes really hard to steer. After work, i got in my car, and everything is fine, no steering issues, no skipping issues, nothing, it ran as if nothing had ever happend. are these signs that my alternator is going bad? i bought a new one just in case. the needle bouncing thing is not normal, but like, it bounced, while normally it justs kinda sweeps. so i dont know if these are signs of it going bad or not.
thanks
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Old Feb 14, 2006 | 09:15 PM
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belts?
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Old Feb 14, 2006 | 09:32 PM
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yea i was thinking that too....
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Old Feb 15, 2006 | 01:42 AM
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any other ideas??
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Old Feb 15, 2006 | 01:54 AM
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when the car is running disconnect the positive battery terminal and see how long the car runs for
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Old Feb 15, 2006 | 05:47 AM
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Originally Posted by carzy driver
when the car is running disconnect the positive battery terminal and see how long the car runs for
BAD BAD BAD!
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Old Feb 15, 2006 | 10:35 AM
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Originally Posted by carzy driver
when the car is running disconnect the positive battery terminal and see how long the car runs for
Yep, BAD BAD BAD BAD


Good way to smoke the entire electrical system.
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Old Feb 15, 2006 | 12:44 PM
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How new is your battery? I have had weird things happen when a battery dies, too.

Edit: Also, make sure the terminals are clean, and good connection to the alternator (ie. look for loose connections)
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Old Feb 15, 2006 | 01:01 PM
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Originally Posted by Icemark
Yep, BAD BAD BAD BAD


Good way to smoke the entire electrical system.
Maybe bad, how I don't know, but does work.
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Old Feb 15, 2006 | 01:29 PM
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if the alternator isn't charging all the idiot lights will be on. sounds like a grounding issue to me or a bad connection at the fuse/junction block.
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Old Feb 15, 2006 | 01:36 PM
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The simple voltage test. Even a cheap DMM will do.

Engine running, headlights & heater fan on high:
Alternator post to alternator frame = 13.5-14 volts steady (verifies the alternator output)
alternator post to battery (+) = 0 volts (verifies the primary + wire)
alternator frame to battery (-) = 0 volts (verifies the primary ground)
Turn off the motor, but leave the lights on.
Battery (+) to battery (-) = ~12.5 volts and holds steady. (verifies battery)
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Old Feb 15, 2006 | 02:18 PM
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I've been having problems with my voltage lately too.

I left my lights on the other day. I got my car jumpstarted and let it run for about an hour. I shut it down and started it, barely started.

When I went to get my alternator tested it came out fine. I still need to get my battery tested...

Anywho, I'm thinking it's a wiring problem. Ah well, I'll find out this weekend and let you know.
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Old Feb 15, 2006 | 09:58 PM
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well i tested the battery, and it said to replace it, so ill start there, but the battery isnt that old, maybe a year, year and a half at most.
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Old Feb 15, 2006 | 10:04 PM
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yea i dont think its the alternator any more because the idiot lights arent on, and the voltemeter still reads 14....so its probably the battery or grounding.
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Old Feb 15, 2006 | 10:15 PM
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check the battery connections and make sure that the battery is secure..if the positive touches anything .it cuts power(sometimes ,BAM..nothin)..look for arc marks on the hood where the battery is..maybe it's touchin the hood..(off chance..but known to happen)
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Old Feb 15, 2006 | 10:36 PM
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yea...i remember that happening to me before, where the positive terminal was loose....so that was the first thing i checked and it was ok....i just replaced the battery so we'll see what happens i guess.....and altho i do have the apexi super grounding system, i think the grounds are ok....but i could be wrong.
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Old Feb 15, 2006 | 10:53 PM
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Originally Posted by Icemark
Yep, BAD BAD BAD BAD


Good way to smoke the entire electrical system.
still no reason why it's bad, and don't pull cause you could fry your ecu crap.
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Old Feb 15, 2006 | 11:06 PM
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well im going to go with its a grounding issue and you should check them anyways, this is just a reason to.

As for the BAD BAD BAD!!! pulling the positive cable off while the car is running can create a huge voltage spike which can fry EVERYTHING! so, unless you really really love rewiring and soldering and spending lots of pointless money, i wouldnt do that or suggest it anymore
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Old Feb 15, 2006 | 11:31 PM
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Originally Posted by carzy driver
still no reason why it's bad, and don't pull cause you could fry your ecu crap.

because full fielding these alternators makes them run VERY hot.
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Old Feb 15, 2006 | 11:41 PM
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Originally Posted by Karack
because full fielding these alternators makes them run VERY hot.
understandable, but even then if the alternator is dead, the car will not run more than a minute or 2, if that.
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Old Feb 15, 2006 | 11:45 PM
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well it can damage the alternator, not something that is advisable when doing a few simple checks are much easier than replacing the now faulty alternator.
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Old Feb 15, 2006 | 11:51 PM
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Originally Posted by Tournapart
well im going to go with its a grounding issue and you should check them anyways, this is just a reason to.

As for the BAD BAD BAD!!! pulling the positive cable off while the car is running can create a huge voltage spike which can fry EVERYTHING! so, unless you really really love rewiring and soldering and spending lots of pointless money, i wouldnt do that or suggest it anymore
I love to rewire and solder. as for the power spike, I know I'll get flamed for this but I don't care, isn't that why there's fuses. I know of one event somewhat like this, my dad had a recall preformed on his truck and the tech at Dodge connected the battery backwards fired the ecu and main harness. If too much power is a problem then why do many go with FD alternators that put out 50 more amps? also why don't we hear more about people frying their electrical when they jump batteries.
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Old Feb 15, 2006 | 11:58 PM
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don't mind his statement, it is false. disconnecting the battery will not cause a HUGE voltage spike and fry everything in the car... it may cause a small one but the fuse is there for a reason.
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Old Feb 16, 2006 | 12:06 AM
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Originally Posted by Karack
don't mind his statement, it is false. disconnecting the battery will not cause a HUGE voltage spike and fry everything in the car... it may cause a small one but the fuse is there for a reason.
thank you
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