What sense is there in a three way switch with an off position? yes, if you turn it off the other switch will not work.

three-wire alternator include the battery positive wire, the voltage sensing wire, and the ignition input wire. The battery positive wire connects to the starter. The voltage sensing wire connects to the battery, and the ignition wire connects from the alternator to the key switch.

Shut off the chime ? You want to shut off the chimes or they don't work ??>?? Which chime ?
Audible Warnings Circuit Description
Safety Belt Warning Chime
Voltage is supplied to the body control module (BCM) through the following components when the ignition switch is in the START or RUN position:
• The GAUGES fuse 4
• CKT 39 (PNK)
When you first turn the ignition switch to the START or RUN position, a class 2 signal from the BCM is sent to the instrument cluster logic turning ON the fasten seat belt indicator. The indicator comes on steady for 20 seconds and then flashes for another 55 seconds if the drivers safety belt remains unbuckled, or goes out when the drivers safety is buckled. When the drivers safety belt is buckled, ground is no longer applied to the BCM through CKT 238 (BLK/WHT) from the seat belt switch causing the lamp and chime to go out. The chime will only sound for about the first 5 seconds of the ignition on cycle.
Key-In Warning Chime
Voltage is supplied at all times to the BCM through the following components:
• The Underhood Fuse Block TBC fuse
• CKT 1140 (ORN)
The chime sounds if all of the following conditions exist:
• The key is in the ignition switch.
• The ignition switch is in one of the following positions:
- ACC
- LOCK
- OFF
• The LH front door is open.
When the ignition key is in the ignition switch and the LH front door is open, the ignition key alarm switch closes. The LH door jamb switch also closes. When both of the switches close, the Body Control Module (BCM) senses ground through the following components:
• CKT 126 (TAN)
• The LH Door Jamb Switch
• CKT 1050 (BLK)
• SP203
• C203 cavity F12
• G203
The chime will sound for as long as the door is open and the key is in the ignition switch.
Lamps-On Warning Chime
Voltage is supplied through the ILLUM Fuse 12 to the BCM through CKT 1220 (GRY) when the following conditions exist:
• The headlamp switch is in the PARK or Head position
• The ignition switch is not in the RUN or START position
• The IP dimmer switch is not at the dimmest setting.
With the IP dimmer switch at the dimmest setting, the current to the BCM may be too weak to be sensed by the module. When the ignition switch is turned to the RUN or START position, voltage is supplied from the GAUGES Fuse 4 to the body control module through CKT 39 (PNK). When the ILLUM and GAUGES Fuse voltages are sensed at the same time, the alarm is not sounded. The GAUGES Fuse 4 loses voltage when the ignition switch is in one of the following positions:
• LOCK
• OFF
• ACC
I'am assuming the chime stays on all the time .
Chime Always On
Step
Action
Value(s)
Yes
No
1
Was the BCM Diagnostic System Check performed?
--
YES - Go to Step 2
NO - Go to Diagnostic System Check - Body Control System in Body Control System
2
Did you review the audible warnings system operation and perform the necessary inspections?
--
YES - Go to Step 3
NO - Go to Audible Warnings Circuit Description
3
Verify that the chime is always on.
Does the chime operate normally?
--
YES - Go to Testing for Intermittent Conditions and Poor Connections in Wiring Systems
NO - Go to Step 4
4
Turn the ignition switch to the OFF position.
Remove the key from the ignition.
Using the scan tool, enter BCM Data List.
Select Input 1.
Does the KEY IN IGNITION test display NO?
--
YES - Go to Step 5
NO - Go to Step 9
5
Turn the ignition switch to the OFF position.
Remove the key from the ignition.
Move the headlamp switch to the OFF position.
Using the scan tool, enter BCM Data List.
Select Input 2.
Does the PARKLAMPS test display OFF?
Inspect the connections at the BCM. Refer to Testing for Intermittent Conditions and Poor Connections in Wiring Systems.
Are the connections in need of repair?
--
YES - Go to Step 7
NO - Go to Step 8
7
Repair the connections as necessary. Refer to Connector Repairs in Wiring Systems.
YES - Is the repair complete?
--
NO - Go to Step 11
--
8
Replace the BCM. Refer to Body Control Module Replacement in Body Control System.
Is the repair complete?
--
Go to Step 11
--
9
Locate and repair the short to ground in CKT 80 between the BCM connector C2 terminal B9 and the ignition key alarm switch. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.
Is the repair complete?
--
Go to Step 11
--
10
Are the park lamps ON with the switch OFF?
--
Go to Diagnostic Starting Point in Lighting Systems
Go to Step 6
11
Operate the system in order to verify the repair.
Did you correct the condition?
--
System OK
Go to Step 4
Your best bet ,take it to a qualified repair shop.

Drl only work in daytime not at night ???? Daytime running lamps are only suppose to work in day light hours . Low beam & high beams ? none of these work at night ?
Headlamps
The headlamps may be turned on in two different ways. First, when the driver places the headlamp switch in the HEADLAMP position, for normal operation. Second, with the headlamp switch placed in the AUTO position, for automatic lamp control (ALC). During ALC the headlamps will be in day time running lamp (DRL) operation in daylight conditions, or headlamp operation in low light conditions.
Headlamp ON/OFF control is determined by the body control module (BCM) by a signal on the headlamp switch on input circuit when the headlamp switch is in the HEAD position. When the headlamp switch is in the AUTO position, the BCM determines headlamps ON/OFF by the voltage from the ambient light sensor.
If the headlight switch is left in the ON position, the inadvertent power control feature will turn off the headlights approximately 10 minutes after the ignition switch is turned to the OFF position. If the driver places the headlight switch in the ON position after the ignition switch has been turned OFF, or if the ignition switch is in the ACCY position, the headlights will remain on until turned off or the battery runs dead.
The high beam indicator is illuminated when the instrument cluster receives a class 2 serial data message from the BCM that the high beams are illuminated.

Do you know what the BCM is ? Do you know what DTC'S - diagnostic trouble code's are ?
DTC B2575
When the body control module (BCM) senses a request for low beam headlamp illumination, the BCM sends a ground signal to the low beam headlamp relay through the headlamp low beam relay control circuit. The headlamp low beam relay will apply voltage to illuminate the headlamps.

Low and High Beams Headlamps Inoperative
Step
Action
Yes
No
Schematic Reference: Headlights/Daytime Running Lights (DRL) Schematics
Connector End View Reference: Lighting Systems Connector End Views or Body Control System Connector End Views in Body Control System.
1
Did you perform the Lighting System Diagnostic System Check?
YES - Go to Step 2
NO - Go to Diagnostic System Check - Lighting Systems
2
Place the headlamp switch in the ON position.
Change the dimmer switch position from the high to low beam positions several times.
YES - Does the headlamp system operate normally?
NO - Go to Testing for Intermittent Conditions and Poor Connections in Wiring Systems
Go to Step 3
3
Are both high and low beam headlamps inoperative?
YES - Go to Step 4
NO - Refer to Headlamps Inoperative - Low Beams or Headlamps Inoperative - High Beams
4
With a scan tool, observe the headlamp switch parameter.
Does the scan tool indicate ACTIVE? YES - Go to Step 7
NO - Go to Step 5
5
Connect a test lamp between the ground circuit of the headlamp switch connector and battery positive voltage.
Does the test lamp illuminate?
YES - Go to Step 6
NO - Go to Step 9
6
Test the headlamps switch headlamps on signal circuit of the headlamp switch for a high resistance, an open, or a short to voltage. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.
Did you find and correct the condition?
Go to Step 12
Go to Step 8
7
Inspect for poor connections to the BCM. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.
Did you find and correct the condition?
Go to Step 12
Go to Step 10
8
Inspect for poor connections to the headlamp switch. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.
Did you find and correct the condition?
Go to Step 12
Go to Step 11
9
Repair the ground circuit of the headlamp switch.
Did you complete the repair?
Go to Step 12
--
10
Important: Perform the setup procedure for the body control module.
Replace the body control module. Refer to Body Control Module Replacement
Did you complete the replacement?
Go to Step 12
--
11
Replace the headlamp switch. Refer to Headlamp Switch Replacement
Did you complete the replacement?
Go to Step 12
--
12
Operate the system in order to verify the repair.
Did you correct the condition?
System OK
Go to Step 3

Turning ignition switch to start position ! Nothing happens , no click , nothing ?
Circuit Description
Moving the ignition switch to the CRANK position sends a 12 V signal to the PCM Ignition Crank Sense. The PCM verifies that the transmission is in the PARK or NEUTRAL position. The PCM then grounds the control circuit of the START relay. When the START relay is energized it allows voltage to the starter solenoid S terminal.

Starter Solenoid Does Not Click

2
Turn the ignition to the START position.
Does the engine crank?
YES - Go to Testing for Intermittent Conditions and Poor Connections in Wiring Systems
NO - Go to Step 3
3
Install a scan tool.
Turn ON the ignition, with the engine OFF.
With a scan tool, observe the Crank Request Signal parameter in the PCM data list.
Turn the ignition to the START position.
Does the scan tool display Yes?
YES - Go to Step 5
NO - Go to Step 4
4
Turn ON the ignition, with the engine OFF.
With a scan tool, observe the Crank Request Signal parameter in the PCM data list.
Turn the ignition to the START position.
Does the scan tool display Yes?
YES - Go to Step 11
NO - Go to Range Selector Displays Incorrect Range in Automatic Transaxle - 4T80- E
5
Turn OFF the ignition.
Disconnect the Starter relay.
Turn ON the ignition, with the engine OFF.
Connect a test lamp between the battery positive voltage of the Starter relay coil circuit and a good ground.
Does the test lamp illuminate?
YES - Go to Step 6
NO - Go to Step 19

This is troubleshooting info from GM factory service testing and repair manual .A scan tool isn't necessary , you could use a test light if you knew which pins at the PCM . For example , testing Crank Request Signal parameter in the PCM data list. Find this wire circuit at the PCM , with a test light .When turning the key to start position ,does the test light light ? A factory scan tool just cuts down the time of diagnoses . A wiring diagram is a must for diagnosing this . Free wiring diagrams can be found at
http://www.bbbind.com/free_tsb.html There are videos on youtube on basic automotive electrical trouble shooting , Control module diagnostics . That is if you don't know how to already .

Probably not. The red light indicate idle mode. The woofer might have an auto-sense switch. When activated the subwoofer turns on when an audio signal is sensed at the subwoofer input.
Such switches often have three positions:
Idle (Somewhat off, but not quite)
Auto (Turns on the woofer when audio signal is detected)
Allways on. (The woofer is allways on - you might hear humm in the woofer when no audio signal is present)

The seat belt warning chime is controlled by the central timer module ! You can't just disconnect fuses , other things may stop working !
Safety Belt Warning Indicator Lamp and Chime
The safety belt indicator and chime feature is controlled by the CTM. The driver safety belt switch is hardwired to the CTM. If at any time during the first 60 seconds after the ignition switch is placed in position II, if the driver safety belt is sensed as being unfastened, the CTM will process the input, and in turn, output a signal to the CTM through a hardwired circuit. In turn the CTM will output a visual warning to the instrument cluster. If at any time during the first six seconds after the ignition switch is place in position II and the safety belt is not fastened, the safety belt warning chime will sound.
When the seat belt is connected the warning still chimes ? Could have code stored in the CTM .
B1464 Safety belt switch circuit short to battery CTM Go To Pinpoint Test B .
SoW

Any switch the same size will work there fine,
It must have the three pins,com, nc, no on the switch.

Yes it does.
The new switch is the problem. The old toggle had a momentary ON when turned on and a jumper wire on two of the three toggle contacts.

If you have the R/T with the onboard computer, you can reset the light through that. If not, there is a very simple reset sequence. 

Begin with the vehicle off. 
Turn the key to the ON position, but do not start the engine.
Press the accelerator pedal to the floor and release it three times.
Turn the key to the OFF position. 

Now if you turn the key on or start the engine, you should see that the light has reset itself, and will only come back on after 3000 miles, or if the ECU senses an oil problem. 

It will be one of three things: #1 faulty Wax/Lift circuit board that controls the lift motor,#2 the motor itself, or #3 a faulty home switch, which is the white plastic switch in the base of the machine which senses the home position or zero degrees elevation.