3rd Generation Specific (1993-2002) 1993-2002 Discussion including performance modifications and Technical Support Sections.
Sponsored by:

Bad Alternator??

Thread Tools
 
Search this Thread
 
Old 05-04-07, 07:09 PM
  #1  
Registered User
Thread Starter
iTrader: (61)
 
purerx7's Avatar
 
Join Date: Apr 2004
Location: Los Angeles, CA
Posts: 7,334
Likes: 0
Received 5 Likes on 4 Posts
Bad Alternator??

Im starting to think that a lot of my problems might be caused from a bad alternator. Car runs fine when drive, boosts fine, pulls fine, has an idle problem and will stall at a light if my AC is running. I took it for a spin around the block came into the garage and put it in park. Car started bucking and shaking heavily, was only seeing -9" vacuum with the running lights on. Than i thought perhaps its an electrical load problem, i than turned on the headlights and the car immediately stalled. So im assuming either is a bad alternator or something wrong in the wiring harness.

Any help would be great, also when im turning into the garage at full radius car starts to buck like its going to stall.

I also noticed the radiator fans were not on but i only ran the car for a few minutes, i thought they turned on at a certain temp so maybe the engine was not hot enough.


Thanks guys
Old 05-04-07, 09:48 PM
  #2  
Senior Member

iTrader: (4)
 
sbnrx7's Avatar
 
Join Date: Feb 2007
Location: Tallahassee, FL
Posts: 442
Likes: 0
Received 6 Likes on 5 Posts
Ok, after this stalling does the engine fire right back up? Does it sound like the starter is struggling?
Old 05-05-07, 10:51 AM
  #3  
Registered User
Thread Starter
iTrader: (61)
 
purerx7's Avatar
 
Join Date: Apr 2004
Location: Los Angeles, CA
Posts: 7,334
Likes: 0
Received 5 Likes on 4 Posts
Originally Posted by sbnrx7
Ok, after this stalling does the engine fire right back up? Does it sound like the starter is struggling?
yes fires right back up, starter and battery were replaced not to long ago.
Old 05-05-07, 11:08 AM
  #4  
Senior Member

iTrader: (4)
 
sbnrx7's Avatar
 
Join Date: Feb 2007
Location: Tallahassee, FL
Posts: 442
Likes: 0
Received 6 Likes on 5 Posts
The symptoms you discribe sound like an alternator going bad but, when that happens, the battery drains trying to compensate for the lack of electricity being generated by the alternator. The result being that when you try and restart, the starter stuggles or when its running and you turn things on, like lights, the engine idle rmps drops as the ignition system is also running soley off of battery power. If this is not the case then I would start checking ground connections as well as all of the wires to the alternator. I recently replaced the small wires that plug into the top of the alternator via a connector because they were brittle and broken. Check these out aswell.
Old 05-07-07, 06:43 AM
  #5  
bryant

 
bryant's Avatar
 
Join Date: May 2002
Location: montgomery
Posts: 1,509
Likes: 0
Received 0 Likes on 0 Posts
take the alt off and get it tested they do it free at most auto parts places.
Old 05-07-07, 08:42 AM
  #6  
What's your point ?

 
CantGoStraight's Avatar
 
Join Date: Feb 2001
Location: Gainesville, Fla.
Posts: 3,573
Likes: 0
Received 0 Likes on 0 Posts
While a bad alternator can cause the engine to do strange things (low voltage readings changes howthe ECU see's the information the sensors are providing) I wasn't aware it would change your vacuum reading.
Old 05-07-07, 09:49 AM
  #7  
Senior Member

iTrader: (1)
 
Nat6c's Avatar
 
Join Date: Jul 2005
Location: Katy Tx
Posts: 376
Likes: 0
Received 0 Likes on 0 Posts
as stated above, remove alt. and get it checked at auto zone or oreily's, IF it chekcs out good. then get a compression test. i've seen quite a many that due ot low compression, when ever heavy load I.E. A/c compressor kicks on at light. vehicle dies. but perfect any other time. just a .02 note. to keep an eye on.

*note: if you keep it reved around 1000-1100, and turn on the lights to the first click so dash come on, then second click for headlights, does the dash dim more? and does it brighten up when the revs go up???




Los
Old 05-07-07, 12:23 PM
  #8  
Burnout

 
rx73rotorj's Avatar
 
Join Date: Oct 2005
Location: Iowa
Posts: 289
Likes: 0
Received 0 Likes on 0 Posts
I had the same problem in 2 of my cars and it was just the wiring was bad need new wires and connections and the alternator was bad too but i would do what they said about getting the alternator checked first.
Old 05-07-07, 01:21 PM
  #9  
Constant threat

 
bajaman's Avatar
 
Join Date: Jul 2001
Location: near Wichita, Kansas
Posts: 4,952
Received 35 Likes on 31 Posts
As a few others have said, get your alternator checked out first. IF it is bad, voila' you are fixed. If it isn't then you can narrow your search further.

Good luck!
Old 05-07-07, 05:07 PM
  #10  
Registered User
Thread Starter
iTrader: (61)
 
purerx7's Avatar
 
Join Date: Apr 2004
Location: Los Angeles, CA
Posts: 7,334
Likes: 0
Received 5 Likes on 4 Posts
*note: if you keep it reved around 1000-1100, and turn on the lights to the first click so dash come on, then second click for headlights, does the dash dim more? and does it brighten up when the revs go up???




Los[/QUOTE]

Los, the car runs better with one click, when the running lights are on car maintains a higher idle and seems to pul a little bit better. The lights do not dim or brighten when the revs go up, its a constant color.
Old 05-07-07, 05:07 PM
  #11  
Registered User
Thread Starter
iTrader: (61)
 
purerx7's Avatar
 
Join Date: Apr 2004
Location: Los Angeles, CA
Posts: 7,334
Likes: 0
Received 5 Likes on 4 Posts
Originally Posted by rx73rotorj
I had the same problem in 2 of my cars and it was just the wiring was bad need new wires and connections and the alternator was bad too but i would do what they said about getting the alternator checked first.
I was hoping you could elaborate on where the wiring was bad?

thanks
Old 05-08-07, 03:15 PM
  #12  
~17 MPG

iTrader: (2)
 
scotty305's Avatar
 
Join Date: Jan 2004
Location: Bend, OR
Posts: 3,284
Received 224 Likes on 151 Posts
I've heard of some people having problems with the wire between the battery and the alternator. While the engine is running, use your multimeter and measure voltage across that wire. Put the black lead of the meter on the (+) terminal of the battery, and put the red lead of the meter onto the large alternator wire (the nut is covered with a rubber cap). If the wire is good, the meter should display a very low voltage (less than 0.3V). If the wire is bad, it will be absorbing power, and you'll read a higher voltage. If you read more than 0.5V, you should definitely replace the wire.


You can check the ground wire in the same way: while the car is running, measure the voltage between the (-) battery terminal and the chassis of the car. You should see less than 0.5V across that wire.

-s-
Old 05-19-07, 09:43 PM
  #13  
Registered User
Thread Starter
iTrader: (61)
 
purerx7's Avatar
 
Join Date: Apr 2004
Location: Los Angeles, CA
Posts: 7,334
Likes: 0
Received 5 Likes on 4 Posts
k thanks guys, im going to check out some of the options you listed, I also noticed today, if I put the windows down while retracting the sunroof, the sunroof goes ALOT slower than it normally would, not sure if this is any help or not.
Old 06-08-07, 02:55 PM
  #14  
Registered User
Thread Starter
iTrader: (61)
 
purerx7's Avatar
 
Join Date: Apr 2004
Location: Los Angeles, CA
Posts: 7,334
Likes: 0
Received 5 Likes on 4 Posts
still having this issue...i have my car apart all over the garage so now would be the best time to fix the problem
Old 06-09-07, 12:23 PM
  #15  
Patience

iTrader: (1)
 
spandy's Avatar
 
Join Date: Jun 2006
Location: Oregon
Posts: 1,483
Likes: 0
Received 0 Likes on 0 Posts
Originally Posted by purerx7
k thanks guys, im going to check out some of the options you listed, I also noticed today, if I put the windows down while retracting the sunroof, the sunroof goes ALOT slower than it normally would, not sure if this is any help or not.

Why would you want to move all three at the same time anyway? Anyway, that is normal. Any vehicle's windows/sunroof is going to slow up in operation when 20 million other accessories are being run at the same time.

I just rebuilt my alternator, parts cost less than 15 bucks.
Old 06-09-07, 12:38 PM
  #16  
Senior Member

iTrader: (1)
 
preludesh2000's Avatar
 
Join Date: Feb 2004
Location: ohio
Posts: 688
Likes: 0
Received 0 Likes on 0 Posts
putting the lights on ...makes it sound like the alt. but it would be hard to start when you turned it off, if it even started...
check the battery with a voltmeter ...go for a drive and checkthe battery again...if its low ...its your alt.

brad
Old 06-09-07, 12:57 PM
  #17  
Blithering Idiot

 
dontlift's Avatar
 
Join Date: Jan 2007
Location: NE Pa
Posts: 338
Received 1 Like on 1 Post
Originally Posted by purerx7
still having this issue...i have my car apart all over the garage so now would be the best time to fix the problem
now would be the best time to get the alternator tested
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
The1Sun
1st Generation Specific (1979-1985)
7
09-18-15 07:13 PM
The1Sun
New Member RX-7 Technical
5
09-15-15 04:45 PM
The1Sun
1st Generation Specific (1979-1985)
0
09-07-15 10:21 PM



Quick Reply: Bad Alternator??



All times are GMT -5. The time now is 01:10 PM.