My Sc300 BATTERY LIGHT!
04-01-09 | 10:11 PM
#16
you need to be more clear in your instruction....
with the vehicle off, a fully charged battery will be between 12.6 and 12.8 volts. 75% charged, 12.4-12.6 volts, 50% 12.2-12.4%, 25% 12.0-12.2 volts, and below 12 volts = 0-25% charge...
with the vehicle running, you should have somewhere between 13.4 and 14.4 volts, depending on amp draw and outside temperature...
if the battery is significantly below 12 volts, suspect a dead cell, however, it is possible for the battery to be discharged even below 10 volts and make a full comeback once it is charged (out of the car, slow charge). If it is below 13.4 volts while running, suspect a bad alternator...
neither one of these tests are guarantees, which is why I recommend having them professionally tested...
with the vehicle off, a fully charged battery will be between 12.6 and 12.8 volts. 75% charged, 12.4-12.6 volts, 50% 12.2-12.4%, 25% 12.0-12.2 volts, and below 12 volts = 0-25% charge...
with the vehicle running, you should have somewhere between 13.4 and 14.4 volts, depending on amp draw and outside temperature...
if the battery is significantly below 12 volts, suspect a dead cell, however, it is possible for the battery to be discharged even below 10 volts and make a full comeback once it is charged (out of the car, slow charge). If it is below 13.4 volts while running, suspect a bad alternator...
neither one of these tests are guarantees, which is why I recommend having them professionally tested...
04-02-09 | 08:42 PM
#17
Thread Starter
Driver School Candidate
Joined: Jan 2009
Posts: 21
Likes: 0
From: Bay Area,CA
well im going to return the alternator tomorrow and get it replaced.. i hope that it was the problem... yesterday it started up just fine again.. started it up this morning but the battery light came back on...
04-03-09 | 06:25 AM
#19
if they tested good on the car, then there is something wrong with the light... if they tested good off the car, then I recommend you have them tested on the car and see what the tests say...
04-04-09 | 11:51 AM
#20
is the battery light flashing or constantly on? i had a problem like this. had to add a 4 guage wire from the batt terminal of the alternator to the positive battery terminal. do a quick easy check first. get a pair of jumper cables and clip one jumpercable to the negative battery terminal to a good ground. then attach the other jumpercable to the positive battery terminal to the batt terminal on the alternator. WITH THE CAR OFF. then turn on the car and if your battery light goes away then you solved your problem. then disconnect one cable to narrow it down. good luck
04-04-09 | 02:00 PM
#21
Tested on the car.
The light is steady on. I will try the jumper cable deal today. Before I got the car it sat for over a year because of fuel pump issues fixed that and the battery light was on for them too.
The light is steady on. I will try the jumper cable deal today. Before I got the car it sat for over a year because of fuel pump issues fixed that and the battery light was on for them too.
04-09-09 | 10:35 PM
#22
So I'm guessing that fixed it. Was it the groundwire? Or alt wire?
04-12-09 | 12:35 PM
#23
I dropped the ball on that, the light went out for about 30 miles of a drive stopped at a gas station for a Coke and when I started ddriving again it came back on. So i need to do the jumper cable test.
04-12-09 | 01:01 PM
#24
just did the jumper cable check and the light never went out the car was running for a few minutes.
Does it need to run longer or should the light have been off to begin with for this test?
part three--- I just had it tested on the car again, pushed down on my new serpentine belt and it flexed over half an inch=tensioner is shot, going to be driving the jeep till i get a new tensioner which should be on thursday.
Until then thanks topdog got me motivated to fix it.
Does it need to run longer or should the light have been off to begin with for this test?
part three--- I just had it tested on the car again, pushed down on my new serpentine belt and it flexed over half an inch=tensioner is shot, going to be driving the jeep till i get a new tensioner which should be on thursday.
Until then thanks topdog got me motivated to fix it.
Last edited by GSXRMack; 04-12-09 at 06:09 PM. Reason: no sense in three posts in a row
04-16-09 | 12:33 PM
#25
I changed the tensioner out and still the same problem Its squealing like a SOB from the alternator so a new one is on the way. Any one just change the pully on the alternator?
04-16-09 | 06:17 PM
#26
just did the jumper cable check and the light never went out the car was running for a few minutes.
Does it need to run longer or should the light have been off to begin with for this test?
part three--- I just had it tested on the car again, pushed down on my new serpentine belt and it flexed over half an inch=tensioner is shot, going to be driving the jeep till i get a new tensioner which should be on thursday.
Until then thanks topdog got me motivated to fix it.
Does it need to run longer or should the light have been off to begin with for this test?
part three--- I just had it tested on the car again, pushed down on my new serpentine belt and it flexed over half an inch=tensioner is shot, going to be driving the jeep till i get a new tensioner which should be on thursday.
Until then thanks topdog got me motivated to fix it.
if you want to see if the tensioner is your problem, put a wrench or ratchet on the tensioner itself - use the tool to apply more pressure on the belt...
for the record, I don't think you have a belt problem...
OH, damn... just read the last post...
told ya so!
so, yah, just changing the pulley on the alternator won't do anything - if its making noise, its the bearings inside...
04-16-09 | 10:16 PM
#27
And thats what I needed to hear about the alternator. Oh and a damn water pump costs the same as the alternator if its the 11 bolt one. if not its a 50 buck one. Oh well I will be changing the alternator on saturday part comes in 3pm but I work Noon to Midnight, so on saturday we will have hopefully have closure on this.
Thanks again you guys we are getting closer.
04-17-09 | 11:53 PM
#28
Ok get this ****.
I drove it today to work and it squeaked and squealed for a while then once I made it to the highway it stopped making noise after I revved a bit to get into traffic. Today was 20* warmer than when I was messing with the tensioner. What gives? Did I just order a alternator for no reason? Hell I got tomorrow so I will put the alternator on and try it out for giggles I guess. Going to paint a line on the crank pulley to see if it is separating and causing a slip when cold(read about that on another thread. Wish me luck.
04-19-09 | 11:36 AM
#29
Problem almost solved. I need to find the thread but i painted a white line on the crank/harmonic balancer and voila!!!! the two lines do not match up after a spirited drive. returning alternator and getting a oem crank pulley/harmonic balancer.
06-27-09 | 01:09 AM
#30
same thing happened to me earlier this week. A new alternator, serpentine belt, and battery later i stumble onto this thread. Wish i would have found it sooner. Goin to do the crank/harmonic balancer test tomorrow....
sventhemac - how hard was the removal and installation of the crank/balancer?
(hijacking not intended, just desperate...)
sventhemac - how hard was the removal and installation of the crank/balancer?
(hijacking not intended, just desperate...)
Last edited by BrownGuy; 06-27-09 at 07:59 AM.