Electrical system flickering in 1999-2003 fulll-size (Suburban, Hoe, Silverado)

[DMC12]

When the engine is idling, the lights flicker (like a movie projector or flourescent light). It also shows up in the gear indicator, radio display, anything that lights up.

What causes this

[bowtiebandit]

The General has just released a fix for this problem. It has to do with re wiring the alternator 4-wire plug.

[DMC12]

Originally posted by bowtiebandit
The General has just released a fix for this problem. It has to do with re wiring the alternator 4-wire plug.

Thanks bandit:bandit: Is there a spefic bulletin# or recall# I can give the service consultant when I go to the dealer?

[bowtiebandit]

This is the actual bulletin,although it does not say anything about the headlights it does fix it. We've actually been using it on other models also.
Transmission 1-2 Shift Shudder, Vibration, Slips, Chuggle (Install Generator Voltage Sense Circuit) #02-07-30-030 - (08/09/2002)
Transmission 1-2 Shift Shudder, Vibration, Slips, Chuggle (Install Generator Voltage Sense Circuit)
2001-2003 Chevrolet Silverado

2001-2003 GMC Sierra

with 4L60-E Automatic Transmission (RPO M30)

Condition
Some customers may comment that the transmission slips, a shudder, chuggle, or vibration is felt when the transmission shifts from first to second gear.

Cause
A 12 Hz electrical feedback from the charging circuit may be affecting the transmission pressure control solenoid, causing a fluctuation of the line pressure within the transmission.

Diagnostic Tip
Road test the vehicle under the following conditions:

Throttle position is less than 15 percent.
Engine coolant and transmission fluid are at full operating temperature.
The outside ambient temperature is warmer than 24°C (75°F).
If the condition is present, disconnect the generator 4 cavity connector (2 wires in the connector) and retest.

If the condition is no longer present, perform the correction listed below.

If the condition remains unchanged, the condition will not be corrected with this procedure. Look for other causes of the condition.

Correction
Install an external sense lead to the generator assembly. This is accomplished by adding a wire from the generator four wire connector to the generator output BAT terminal.

Disconnect the negative battery cable from the battery/batteries.
Slide the protective boot on the generator BAT terminal aside and remove the retainer and wire cable from the BAT terminal.
Unplug the generator 4-cavity terminal from the top of the generator.
Remove and save the orange weatherpack seal and CPA from the 4-way connector.
Using the proper terminal removal tool, remove the two wires from the 4-way connector.
Install a red cavity plug, P/N 12059168, into cavity "A" of the new 4-way connector, P/N 12186568.
Install the brown (Circuit 25) wire of the vehicle wiring harness into cavity "B" of the new 4-way connector.
Install the gray (Circuit 23) wire of the vehicle wiring harness into cavity "C" of the new 4-way connector.
Obtain a piece of 0.80 mm/18GA black wire, 254 mm (8 in) long.
Install a red terminal seal, P/N 12048086, and terminal, P/N 12048074, (crimp and solder) on one end of the new black wire.
Install the new black wire into cavity "D" of the new 4-way connector.
Reinstall the connector seal and CPA, from the original connector, to the new connector.
Plug the 4-way connector into the generator.
Route the black wire to the generator BAT terminal, sliding the wire into the small end to the output terminal boot, along side the generator output wire.
Crimp and solder the ring terminal, P/N 02977821, on the open end of the new black wire.
Place the generator output wire and the new black wire onto the generator BAT terminal and install the retainer. Tighten
Tighten to the BAT terminal retainer to 9 N·m (80 lb in).

Connect the negative battery cable. Tighten
Tighten the battery cable retainer to 17 N·m (13 lb ft).

[Shortbus]

Goodjob bowtiebandit
Keep the good info flowing in here.

[theffv]

Have a 2001 1500 4x4 with flickering dash and headlights that would occur in idle and disappear when running but also noticed dash and headlamps were dimming over time. Problem was getting worse and the truck wouldn't start on two seperate isolated instances. Idle didn't seem to be where it should be.

Performed the "transmission" workaround listed above but it didn't solve the problem.

Then, it was diagnosed with a bad battery which was changed but didn't solve the problem.

A dealer wanted $450 just for a new altenator before labor!
Had another dealer install a new altenator for $250 - Problem Solved!

(`'·.¸ ¸.·'´)
*B E S T*
(¸.·'´ `'·.¸)
TheFFV