Battery not charging issues

PREACHERWIFE31RB

MEMBER
2003 GMC ENVOY
6 CYL
4WD
AUTOMATIC
150,000 MILES

Got a new battery for the car, replaced the alternator and it ran fine other than it needed two coils. So I parked it, replaced the spark plugs and two weeks later replaced the coils. No battery issues before I parked it to replace the coils. I replaced the coils and the battery was completely dead. Doors wouldn't even unlock. Jumped it and it ran smoothly. That night, went to leave and the headlights didn't work. The brights worked fine, but not my dims. Parked it again. Figured it was the relay since the fuses were good. The next day, went to start it and the battery was dead, again. Jumped it and let it run for a while. Went to town later, and the battery not charging display came on. The battery usually reads just above 14 on the gauge, but now it's reading 17 and just over 17. The battery not charging display only comes on when pressing on the gas. When I stopped at stop signs, it went off. Any insight?

1 Reply

JACOBANDNICKOLAS

MECHANIC
109,747 POSTS

Hi and thanks for using 2CarPros.

If the battery is getting 17 volts, the regulator is bad. Also, this can cause many electrical issues and even a fire.

The voltage regulator is part of the alternator. With that in mind, remove it and have it bench tested.

____________________________

Here are directions, if needed, for removal and replacement. All attached pictures correlate with these directions.

__________________________

GENERATOR REPLACEMENT
REMOVAL PROCEDURE
1. Disconnect the battery negative cable.
2. Remove the drive belt.

Picture 1
3. Disconnect the battery positive cable nut (1) on the generator.

Picture 2
4. Remove the A/C line mounting bracket bolt at the engine life hook.

Picture 3
5. Remove the right engine lift hook bolts and remove the lift hook.

Picture 4
6. Remove the 3 generator mounting bolts and remove the generator.

INSTALLATION PROCEDURE
1. Install the generator and secure the generator with 3 bolts.

NOTE: Refer to Fastener Notice in Service Precautions.

Tighten
Tighten the generator bolts to 50 N.M (37 lb ft).

Picture 5
2. Connect the battery positive cable to the generator and secure the positive cable with the nut (1).

Tighten
Tighten the generator positive cable nut to 9 N.M (80 lb in).

Picture 6
3. Install the engine lift hook and secure the lift hook with 2 bolts.

Tighten
Tighten the bolts to 50 N.M (37 lb ft).

Picture 7
4. Install the A/C line bracket to the lift hook and secure the bracket with the bolt.

Tighten
Tighten the A/C line bracket bolt to 10 N.M (89 lb in).

5. Install the drive belt.
6. Connect the battery negative cable.

____________________________

Again, have the alternator bench tested to confirm the regulator is working.

Let me know what you find or if you have other questions.
Joe

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