Alternator

2011 BUICK LA CROSSE
69,000 MILES • 3.6L • 6 CYL • 2WD • AUTOMATIC
Avatar
JAMESRBRAD
  • MEMBER
  • 4 POSTS
I am having a problem with my wife's car where for the last two mornings upon initial startup the car will not start. No noise or clicking. However, the parking lights and dash lights illuminate and the check engine light shows. The afore mentioned lights stay on until i detach the negative terminal cable wait a few seconds then reattach the negative terminal. Unfortunately when i disconnect the battery i lose any possible check engine code. I took it in for a battery check and I have been told that my alternator is generating 14.7 volts and i should replace it before it ruins my battery. They said the favorable range should be between 12.5 and 13.5 volts. Is this accurate? and is it possible that the overcharging has caused an electrical issue in the ignition system?
Jan 31, 2018 at 9:43 AM
Advertisement
Avatar
ASEMASTER6371
  • CERTIFIED EXPERT
  • 52,796 POSTS
Good afternoon.

The acceptable range for charging system is 14 to 14.5 volts. 14.7 is a tad high but is not an indicator to replace the alternator.

did they load test the battery?

also, do not remove the cable and reattach. It does nothing. if there is any codes they must be documented, diagnosed and necessary repair performed.

Roy
Jan 31, 2018 at 11:13 AM
Avatar
JAMESRBRAD
  • MEMBER
  • 4 POSTS
I am not sure about a load test. The car was running but at an idle at the time they checked the voltage.
And as far as disconnecting and reattaching the negative terminal not doing anything, in my case something must have got reset because once i reattached the cable my car starts right up. Two mornings in a row.
Jan 31, 2018 at 11:33 AM
Advertisement
Avatar
ASEMASTER6371
  • CERTIFIED EXPERT
  • 52,796 POSTS
Okay, then you have other issues.

did the check engine light come back on?

Roy
Jan 31, 2018 at 11:44 AM
Avatar
JAMESRBRAD
  • MEMBER
  • 4 POSTS
Not until the next morning when it wouldn't start again.
And i may not have made myself clear but in the morning when i try to start the car and it wont turnover the parking lights and the dashboard come on but wont go out until i disconnect the battery. I waited about 10 minutes just to see and they stayed illuminated.
Jan 31, 2018 at 12:46 PM
Avatar
ASEMASTER6371
  • CERTIFIED EXPERT
  • 52,796 POSTS
OK, would love to have the code. something is locking out the starter relay from working. that is the pcm. it is being told to lock it out. thats why the code would be very helpful in trying to help

when you pulled the cable the pcm forgot the command. thats why it started

Roy
Jan 31, 2018 at 1:13 PM
Avatar
JAMESRBRAD
  • MEMBER
  • 4 POSTS
Yep. I took the car to a mechanic a there is no code logged. I left the car so they can try to get the fault tomorrow morning. Thanks.
Jan 31, 2018 at 4:15 PM
Avatar
ASEMASTER6371
  • CERTIFIED EXPERT
  • 52,796 POSTS
your welcome. keep us updated

Roy
Jan 31, 2018 at 11:00 PM