Battery or Altenator

Stpman

Well-known member
Joined
Apr 10, 2008
Messages
376
Location
Niagara Region
It never rains it pours

Cavalier 2.2l

Symtoms, corrosion all around the bottom of the battery, battery light in dash is on, 12.16 Volts not running and 11.67 Volts running. Is it the battery or the altenator? Battery was used when installed in the car about 2 years ago (could be 5+ YEARS OLD)

Steve
 
Years ago, it was said that if your battery last 5 years you got your monies worth. On my wifes car I'm on my second battery and the car is 18 years old, so they've come a long way. When the engine is running the battery should be charging at around 13 volts or more depending on the amperage of the alternator. It's possible the voltage regulator is going or gone. Parts Source does free alternator testing, check there web site and it's in print. Give them a call. You can also check the engine code.

Last time I exchanged my GM 100 amp alternator the charge was $90.00 cash in Canada. Straight exchange or they rebuild yours.
 
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when engine is running and throttle at least blipped a tad to maybe 2000 rpm, alt is supposed to charge to 13+++ volts but not over 14.8....

and then back off to about 13.3 after a while running...

if the battery measures less then 12.5 with headlights on, AT THE BATTERY TERMINALS DIRECTLY, it's a bad battery...

change the alt, the see if the battery survived...

:thumbs:
 
Sounds like you need an alternator for sure. Have the battery tested while you are at it. It is very possible that that is bad also.
 
Sounds like you need an alternator for sure. Have the battery tested while you are at it. It is very possible that that is bad also.

Have the alt out to be tested but went ahead and replaced the battery because it looked like it had puked all over the battery tray. The alt does look like there is a black burn mark on the pulley end.
 
Nothing on the pulley end to see if the alt failed, UNLESS a winding gave out somehow....hard to believe, but maybe....

have it tested, I still don't like anything much less than 14.8 volts on initial start up, dropping down as it charges....

that is at the alt terminals...

:smash:
 
Nothing on the pulley end to see if the alt failed, UNLESS a winding gave out somehow....hard to believe, but maybe....

have it tested, I still don't like anything much less than 14.8 volts on initial start up, dropping down as it charges....

that is at the alt terminals...

:smash:

Replaced the alternator and all is good. changed out the belt while I was there as it looked dry and cracked (what a PIA)

Thanks for everyones input
 
glad you got it fixed! Battery dead on my sons Cobalt today. Checked the battery before jumping it...dead as a doornail.

Jumped it and let it run...checked the charging with the multimeter....13.3 at idle and 13.6 at 1500 rpms.

Took it to advance auto and had them check bat and charging system. Both checked out good. No draw on the battery either:eek:

Now WTF! Going to let it sit overnight to see if the bat drains. Son said that he didn't leave anything on to drain the battery:skeptic:
 
Nothing on the pulley end to see if the alt failed, UNLESS a winding gave out somehow....hard to believe, but maybe....

:smash:

I think I know what happened, after I replaced the alt it sprung a leak at the corner of the radiator outlet pipe (starts from the head on the pass side does a 180 under the alt and runs along the front of the engine) the leak was right where the black mark on the front case of the alt was. Not a simple thing to replace either had to support the engine and take out the pass side motor mount just to get it out of the head.
 
I once had a GM alternator that powered the electrical stuff in the car but wouldn't charge the battery. took me awhile to figure that one out.
 
I once had a GM alternator that powered the electrical stuff in the car but wouldn't charge the battery. took me awhile to figure that one out.

Yeh, I hear you, I got involved a bit with battery tech in the early 80's doing R&D work with then available Gel Cells...supposedly a lead acid take off, which acted similarly to car batteries.....went through a whole lot of crap developing and certifying a decent backup...found that the battery makers were exaggerating the claims of battery storage ....the discharge power curves were WAY off the beam....so we had to almost double the size of our backup pack...lovely...our M/E had a COW over that one...

:eek:
 
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