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Dan
Dan, Technician
Category: Buick
Satisfied Customers: 23586
Experience:  Independent Shop Experience, 2 Year Automotive Diploma, & Access to Information Database
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1999 Buick lesabre stall after initial start

Customer Question

1999 Buick lesabre stall after initial start
Submitted: 1 year ago.
Category: Buick
Expert:  Dan replied 1 year ago.

Hello, my name is***** the security light stay on or flash? Or does it act normal? Thanks.

Customer: replied 1 year ago.
What security light?
Customer: replied 1 year ago.
Security light?
Expert:  Dan replied 1 year ago.
A security indicator on the dash, you would notice. Unplug the mass airflow sensor and let me know if that helps. Thanks.
Customer: replied 1 year ago.
Battery dead
Charging now
Expert:  Dan replied 1 year ago.

No problem. Let me know how it goes, thanks.

Customer: replied 1 year ago.
Battery charged
Tested goodStarted engine
Battery charge/alternator gauge shows 17+, almost in the red
Expert:  Dan replied 1 year ago.

Disconnect battery and touch cables together for 10 seconds and reconnect. Let me know if that helps charging problem. Thanks.

Customer: replied 1 year ago.
Tried it
No change to alternator gauge indicator
Expert:  Dan replied 1 year ago.

Backprobe the alternator Red wire for a 5 volt turn on signal. Backprobe the Orange wire volt voltage equal to the output stud of the alternator. If the Orange wire has low voltage, the alternator will increase output voltage. Check for voltage on the A/C RLY (COMP) fuse in the upper underhood electrical center. If all are good then replace the alternator. Let me know how it goes or if you have more questions, thanks.

Customer: replied 1 year ago.
I replaced alternator as well
Still charging around 17 volts?
Expert:  Dan replied 1 year ago.

Unplug/replug the PCM a couple times and same with 10 amp PCM fuse in location of 8 at fuse box on right side of dash. Let me know if that helps at all. Thanks.

Customer: replied 1 year ago.
Unplugged both
Still overcharging
Expert:  Dan replied 1 year ago.

Gray wires goes from alterantor to pin29 of connector 2 at PCM. Red wire goes from pin 61 to alternator. Check resistance on both wires between the points, they should each have under 5 ohms. Let me know, thanks.

Customer: replied 1 year ago.
Are you suspecting wire harness or alternator.
Alternator itself is new and was tested before I walked out of autozone.
Expert:  Dan replied 1 year ago.

I'm suspecting wire harness or connection somewhere which we can hopefully figure out after a couple tests. Let me know, thanks.

Customer: replied 1 year ago.
Back at it tomorrow
Thanks
Expert:  Dan replied 1 year ago.

No problem, I'll talk to you then. Thanks.

Customer: replied 1 year ago.
What are the chances of a bad or rusted ground connection.
Would that cause overvoltage
Expert:  Dan replied 1 year ago.

Run a temporary ground from alternator case to battery ground, if that fixes problem then it is.

Customer: replied 1 year ago.
Voltage from positive to negative battery terminals is 12.4 before starting.
Engine running, voltage is 14.77.
Also with engine running, voltage from alternator to body ground is 14.77
Expert:  Dan replied 1 year ago.

That is a good reading so if running additional ground helped you will need to clean ground cables. let me know how it goes, thanks.

Customer: replied 1 year ago.
That would rule out battery, alternator output, alternator to battery positive cable
Expert:  Dan replied 1 year ago.

Before you said it was charging at 17v and now it is charging at 14.7?

Expert:  Dan replied 1 year ago.

Did you run temporary ground?

Customer: replied 1 year ago.
Temporary ground made no difference.
Dash gauge shows 17+
Customer: replied 1 year ago.
This would make me think that either the gauge is faulty or something else is causing the high reading
Expert:  Dan replied 1 year ago.

Disconnect battery and touch cables together for 10 seconds with battery disconnected to try and reset module built into cluster. If that doesn't help the cluster/gauge assembly will need to be replaced. I assumed we were checking voltage with meter from beginning, sorry about misunderstanding. Let me know how it goes, thanks.