Repair 7

An L-pad is essentially a sliding rheostat used in audio setups, be it in your car or in your home audio setup. To calculate the resistance values in an L-pad, you need to test the individual resistors with a multimeter set to resistance. This will then tell you what the individual resistances are of the wires. You can then determine what the resistance value of the L-pad is by checking the setting of the the slide.

Instructions

1

Turnon the circuit with which you are working. Ensure that there is power flowing from the power source to the audio player by turning the multimeter dial tothe voltage setting. Plug the probes to the voltage holes on the face of the multimeter. Touch the red probe to the wire going into the L-pad and the black probe to the wire coming from the L-pad. If the multimeter displays a positive voltage, then you have a live current.

2

Slide the L-pad slide to the topmost setting. Turn the multimeter to the resistance setting and plug the probes into the resistance holes in the face of the multimeter. Put the red probe on one side of the resistor in the L-pad that is connected to the top setting contacts. Place the black probe on the other side of the resistor that is connected to the top settings contacts. Read the resistance value and write it down.

3

Slide the slide down to the next lower setting and place the robes on either side of the resistor connected to those contacts. Write down the resistance value. Repeat this process for all the resistors in the L-pad to obtain the resistance value of the L-pad.

The dash pad on a 2004 Chevrolet Silverado is also called the upper instrument trim panel. This panel runs the entire length of the passenger cabin and must be removed in order to access the gauge cluster and the interior ventilation ducts. This panel also contains the passenger-side assist handle and covers the upper portion of the passenger air bag unit. All 2004 model year Silverados contain this panel, despite their seating or cab configuration.

Instructions

Removal

1

Set the parking brake and turn the air flow control to the vent position. Move the gear selector lever, if equipped with an automatic transmission, to first gear to allow more space between the shift lever and the trim panel. Depress the tilt lever on the steering wheel and tilt the wheel as far down as it will go.

2

Pry off the end panel between the drivers door and the dashboard with a flat-head screwdriver. Pry off the end panel between the passenger door and the dashboard with a flat-head screwdriver. Pry off the instrument panel cluster trim plate bezel with a flat-head screwdriver.

3

Pry the right-side air vents out of the dashboard with a flat-head screwdriver. Insert a flat-head screwdriver through the duct outlet holes and depress the release tabs for the assist handle, then remove the assist handle.

4

Pry the windshield A-pillar moldings away from the pillars until they pop loose with a flat-head screwdriver. Remove the A-pillar moldings. Remove the bolts holding the trim panel to the supporting skeleton underneath the dashboard with a metric socket and a ratchet.

5

Lift up on the trim panel with both hands until the self-contained locking clips pop loose. Disconnect the ambient light sensors electrical connector and then completely remove the upper instrument trim panel from the vehicle.

Installation

6

Reconnect the ambient light sensors electrical connector to the underside of the instrument panel and set it into position. Press down on the panel to seat the panels integrated locking clips.

7

Reinstall the screws holding the trim panel to the dashboard skeleton with a ratchet and a metric socket. Torque the screws to 18 inch-pounds with a torque wrench.

8

Set the A-Pillar moldings into place and press them down until they snap into position on top of the A-pillar skeletons

9

Set the assist handle into position in front of the dash panel and press down on it until it locks into place. Pull on the handle to confirm that it is securely locked into place.

10

Place the vents into position in the air ducts and press down on them until they click into position. Snap the dashboard end panels into position.

11

Snap the instrument panel trim plate bezel into position. Tilt the wheel back to a normal position and shift the gear selector lever, if equipped, back into park.