voltage drops - GM Forum - Buick, Cadillac, Chev, Olds, GMC & Pontiac chat


Everything Electrical & Electronic Have an electrical problem? Lighting, Alternators, gauges, DIC, HUD, etc? Post it here. Please post Audio problems in the Audio forum, and Engine control problems in the appropriate Mechanical forum for your year.

Reply
 
 
 
Thread Tools Search this Thread
Old 02-19-2005, 07:06 PM   #1
Senior Member
True Car Nut
Thread Starter
 
Join Date: Jun 2004
Location: Rochester, NY (college)
Posts: 6,182
Thanks: 0
Thanked 0 Times in 0 Posts
corvettecrazy is on a distinguished road
Default voltage drops

what would be the cause of the voltage to drop into the red zone sitting at a stop light. AC/heat off stereo on low (no subs) It felt like the car was going to die. I popped it into neutral reved it up to 2500 and the volt meter went back up to its normal 13ish volts.

Also on start up the volts take a LONG time to go upto 13ish volts unless I rev it up to 2000 in which it rises more quickly.

any ideas? because my parents solutions suck, and other than me thinking the alt is dying I have no evidance / way to support my side.
corvettecrazy is offline   Reply With Quote
Old 02-19-2005, 07:17 PM   #2
Senior Member
Posts like a Corvette
 
Ol' Timer's Avatar
 
Join Date: Oct 2002
Location: New Jersey - Most of Our Elected Officials Have Not Been Indicted
Posts: 1,483
Thanks: 0
Thanked 0 Times in 0 Posts
Ol' Timer is on a distinguished road
Default

Bad Ground? Crud on the cables? Dead cell in the battery(what does the volt meter read BEFORE you turn the key to engage the starter)? And last, but not least, The Alternator!
Ol' Timer is offline   Reply With Quote
Old 02-19-2005, 07:45 PM   #3
Senior Member
Certified Car Nut
 
Join Date: Oct 2003
Posts: 19,756
Thanks: 0
Thanked 0 Times in 0 Posts
1993 SLE is on a distinguished road
Default

it is the alt, that is what was happening before i installed my 140amp alt.
1993 SLE is offline   Reply With Quote
Old 02-19-2005, 08:11 PM   #4
Senior Member
True Car Nut
 
Join Date: Apr 2004
Location: Three Oaks, Michigan
Posts: 4,879
Thanks: 0
Thanked 0 Times in 0 Posts
opensourceguy is on a distinguished road
Default

Yep, teltale signs your Alternator is failing. Those voltage drops are NOT good for your electronics [or so I have been informed about]. So, my suggestion is to replace it, plus it will eliminate the posibility of being stranded.


-justin
opensourceguy is offline   Reply With Quote
Old 02-19-2005, 08:28 PM   #5
Senior Member
Certified Car Nut
 
Join Date: Oct 2003
Posts: 19,756
Thanks: 0
Thanked 0 Times in 0 Posts
1993 SLE is on a distinguished road
Default

and it is killing your battery at the same time, you might want to replace that too, or you will be on a neverending cycle
1993 SLE is offline   Reply With Quote
Old 02-20-2005, 12:18 AM   #6
Senior Member
True Car Nut
Thread Starter
 
Join Date: Jun 2004
Location: Rochester, NY (college)
Posts: 6,182
Thanks: 0
Thanked 0 Times in 0 Posts
corvettecrazy is on a distinguished road
Default

Quote:
what does the volt meter read BEFORE you turn the key to engage the starter
very very low, maybe the top or just barely out of the red zone.

Quote:
Once the battery has been charged and the car has warmed up you should be around 13v...
I am while running (normally) although at times it will just drop really hard. It is just really slow getting there and doesn't always stay up that high.


Quote:
and it is killing your battery at the same time, you might want to replace that too, or you will be on a neverending cycle
you're funny. I can't even get them to pay for new spark plugs!


Can an alt slowly fail or do they just fail straight out?[/quote]
corvettecrazy is offline   Reply With Quote
Old 02-20-2005, 12:43 AM   #7
Senior Member
Certified Car Nut
 
Join Date: Oct 2003
Posts: 19,756
Thanks: 0
Thanked 0 Times in 0 Posts
1993 SLE is on a distinguished road
Default

Quote:
Originally Posted by corvettecrazy
Quote:
what does the volt meter read BEFORE you turn the key to engage the starter
very very low, maybe the top or just barely out of the red zone.

Quote:
Once the battery has been charged and the car has warmed up you should be around 13v...
I am while running (normally) although at times it will just drop really hard. It is just really slow getting there and doesn't always stay up that high.


Quote:
and it is killing your battery at the same time, you might want to replace that too, or you will be on a neverending cycle
you're funny. I can't even get them to pay for new spark plugs!


Can an alt slowly fail or do they just fail straight out?
[/quote]

no the alt can have a slow painfull death, the gauge should be about 9-10v with the key in the on position
1993 SLE is offline   Reply With Quote
Old 02-20-2005, 08:24 AM   #8
Senior Member
True Car Nut
 
Join Date: Apr 2004
Location: Three Oaks, Michigan
Posts: 4,879
Thanks: 0
Thanked 0 Times in 0 Posts
opensourceguy is on a distinguished road
Default

With ours, it is usually slow and painful, but I have seen Alternators fail just out of the blue. Like my dad'* Suburban, he has a dual battery setup [running just under 2,000CCA total, and this is from the factory]. Because it is a diesel, you really don't need a whole lot of power to keep it running. Just enough to keep the computer on to fire the injectors. And just one day the lights started dimming and the Alternator just quit. Was this a freak incident? Possibly.

What has always happened on the Bonneville, is it would act up for a few weeks, then it would just flat out quit. One day, turn the key and the battery is either dead, or extremely low. This is one of the things that will leave you stranded.. my suggestion is to remove your'*, and put it back on. Carry the necessary tools to remove it, and carry a spare. I can remove mine is less than a minute, but since you have an SII, it will probably be more difficult.


-justin
opensourceguy is offline   Reply With Quote
Old 02-20-2005, 12:30 PM   #9
Senior Member
True Car Nut
Thread Starter
 
Join Date: Jun 2004
Location: Rochester, NY (college)
Posts: 6,182
Thanks: 0
Thanked 0 Times in 0 Posts
corvettecrazy is on a distinguished road
Default

i don't have money to get a spare.

I'm just going to let it ride, and if the car needs a ride because it failed I can shove it in their faces because they are too stupid to trust me.
corvettecrazy is offline   Reply With Quote
Old 04-03-2005, 10:20 PM   #10
Senior Member
Posts like a Supercharger
 
Join Date: Oct 2004
Location: Winchester, Virginia
Posts: 190
Thanks: 0
Thanked 0 Times in 0 Posts
Taylora is on a distinguished road
Default

Hey guys I have the same problem on my 92. But it only does it when the rear defroster is on. Added to the rear defroster is the heater, radio on low, lights and that is about it. It will drop down to about the mark between the red and 14 volts. A curiosity question. I have a 450 cranking amp battery on my car that was put on by the previous owners could there be a problem with the battery being too weak?
Taylora is offline   Reply With Quote
 
 
Reply

Related Topics
Thread Thread Starter Forum Replies Last Post
severe voltage drops jason5983 Everything Electrical & Electronic 8 10-19-2010 11:37 PM
voltage drops after driving 30+km Geforce 1992-1999 5 11-09-2009 12:06 PM
Voltage drops when turning abrubtly reb 1992-1999 3 01-20-2008 03:10 AM
Voltage drops 1994se Everything Electrical & Electronic 18 01-14-2005 07:14 PM
Cruise control drops out TitZonAritZ 1987-1991 2 12-30-2002 07:48 AM


Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off



All times are GMT -4. The time now is 10:55 PM.


We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to Amazon.com and affiliated sites.