LT1-LT4 Modifications 1993-97 Gen II Small Block V8

low voltage

Thread Tools
 
Search this Thread
 
Old 07-09-2008, 11:04 PM
  #1  
TECH Enthusiast
Thread Starter
iTrader: (2)
 
383z's Avatar
 
Join Date: Jun 2008
Location: Houston/Clear Lake, TX.
Posts: 619
Received 57 Likes on 51 Posts

Default low voltage

I'm new and I need some help. I have a bad low voltage problem. In park and neutral the the car has 12 volts., around 11 volt. in drive, and 10 volt. when its in drive and the a/c is on. If I'm driving it and I come to a stop with the a/c on, the volts. drop even more and the car will die if i don't throw it in neutral. I've checked....
  • the battery and put two diffrent ones in the car and the volt. didn't chang
  • changed the alternater 3 times . Its a 140 amp now and it does charge. Its never killed my optima
  • no underdrive pully
  • volt. reading at the battery is the same as the gauge in the car
  • checked all visible grounds
  • and it doesn't have a stereo
I've had this problem since the engine was rebuilt. Can someone post some pictures of all the grounds or describe them with detail where all of them are.I might be missing one and not even know it. I would like to check this off the list before I up grade all the old wires and/or take the car to someone and have the little red wire on the back of the alternator to the juction box redone , which will cost me. If any body would like to put there two cents in on how to fix this problem I would love to hear it.
Old 07-10-2008, 07:39 AM
  #2  
Staging Lane
 
stfuad's Avatar
 
Join Date: Jun 2007
Location: Syracuse, NY
Posts: 72
Likes: 0
Received 0 Likes on 0 Posts
Default

There is a ground on the passanger side engine mount to the block. Another one from the ICM to the fender. One from the Battery to the fender... and... that's it? I forget.

Check the exciter wire from the alt to the pcm, and the battery to alt power wire.
Old 07-10-2008, 03:42 PM
  #3  
On The Tree
 
bobdec's Avatar
 
Join Date: Nov 2007
Posts: 130
Likes: 0
Received 0 Likes on 0 Posts
Default

What year and model are we looking at here ? Wild guess.. is your belt tight (tensioner OK) ? Any squeals with air on ?
Old 07-10-2008, 07:07 PM
  #4  
TECH Enthusiast
Thread Starter
iTrader: (2)
 
383z's Avatar
 
Join Date: Jun 2008
Location: Houston/Clear Lake, TX.
Posts: 619
Received 57 Likes on 51 Posts

Default

Originally Posted by bobdec
What year and model are we looking at here ? Wild guess.. is your belt tight (tensioner OK) ? Any squeals with air on ?
Oh yea, Its a 1993 Z28 and its a speed density car. Yes, the belt is tight because it was a pain to put it back on when I just got done replaced the alternator, and no there aren't any squeals when the air is on.
Old 07-10-2008, 10:32 PM
  #5  
TECH Enthusiast
iTrader: (30)
 
sweet-94z28's Avatar
 
Join Date: Jan 2008
Posts: 679
Likes: 0
Received 0 Likes on 0 Posts

Default

My car has been doing the same thing. I think its the voltage regulator in the alternator.
Old 07-10-2008, 11:37 PM
  #6  
TECH Enthusiast
iTrader: (2)
 
FlamingChicken's Avatar
 
Join Date: Apr 2005
Posts: 546
Likes: 0
Received 0 Likes on 0 Posts
Default

usually a toasted regulator will send your charge level through the roof when you are driving though. i know when mine went out it would reach 18v! when you checked your grounds, did you check the actual ground point? paint or rust will definitely create a poor ground issue.
Old 07-11-2008, 05:16 PM
  #7  
TECH Enthusiast
Thread Starter
iTrader: (2)
 
383z's Avatar
 
Join Date: Jun 2008
Location: Houston/Clear Lake, TX.
Posts: 619
Received 57 Likes on 51 Posts

Default

Originally Posted by FlamingChicken
usually a toasted regulator will send your charge level through the roof when you are driving though. i know when mine went out it would reach 18v! when you checked your grounds, did you check the actual ground point? paint or rust will definitely create a poor ground issue.
Yes, I checked for rust and if the grounds were on paint, and wouldn't a new alternator rule out the voltage regulator?This is a pain the a**



Quick Reply: low voltage



All times are GMT -5. The time now is 11:53 AM.