Intermittently reverse lights do not work

It sounds like the linkage to the transmission needs adjusted or the switch is bad.

Do me a favor. Here are the directions for adjustment. Try this first. The attached pics correlate with the directions.

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2002 Chevy Truck K 1500 Truck 4WD V8-5.3L VIN T
Allison - Automatic Transmission
Vehicle Powertrain Management Sensors and Switches - Powertrain Management Sensors and Switches - Computers and Control Systems Transmission Position Sensor/Switch Adjustments Allison - Automatic Transmission
ALLISON - AUTOMATIC TRANSMISSION
Park/Neutral Position Switch Adjustment

Tools Required
- J 41364-A Park/Neutral Switch Aligner

Caution: Refer to Battery Disconnect Caution in Service Precautions.

Pic 1

1. Disconnect the external wiring harness from the PNP switch (5).
2. Disconnect the shift linkage/cable from the shift lever at the transmission.
3. Use a wrench (1) to keep the shift lever (2) from rotating. Remove the nut (3) from the end of the selector shaft (4). Carefully remove the shift lever (2) from the selector shaft (4).
4. Loosen the two bolts (6) so that the PNP switch may be rotated with some effort.
5. Put the selector shaft in the N (Neutral) position as follows:
5.1. Place a wrench on the selector shaft flats and rotate the shaft to its furthest clockwise position.
5.2. Rotate the selector shaft counter-clockwise two detents.

Pic 2

6. Position J 41364-A over the selector shaft (3) so the two tabs on the tool engage the two slots in the PNP switch (2) just outside the selector shaft. Rotate the PNP switch (2) until the single tab (1) at the other end of the tool engages the single slot at the top of the PNP switch.

Notice: Refer to Fastener Notice in Service Precautions.

7. Hold the special tool in engagement with the PNP switch to maintain alignment of the PNP switch with the selector shaft.
Tighten the two bolts (4) to 27 Nm (20 ft. Lbs.).

Pic 3

Notice:
DO NOT drive the selector lever onto the selector shaft.
DO NOT use an impact wrench in order to tighten the selector lever nut. Hold the lever with a wrench while tightening the nut.
Failure to follow these instructions may result in transmission damage.

8. Reinstall shift lever (2). Install nut (3), by hand, on the end of selector shaft (4). Use a wrench (1) to keep the shift lever from rotating.
Tighten nut (3) to 24 Nm (13 ft. Lbs.).
9. Reconnect the shift selector linkage/cable to the shift lever (2).
10. Connect the external wiring harness connector to the PNP switch.

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Do this and let me know what happens.

Take care,
Joe

I don't know if you need them, but here are the directions for switch replacement. The pics attached correlate with the directions.

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2002 Chevy Truck K 1500 Truck 4WD V8-5.3L VIN T
4L60-E - Automatic Transmission
Vehicle Powertrain Management Sensors and Switches - Powertrain Management Sensors and Switches - Computers and Control Systems Transmission Position Sensor/Switch Service and Repair Procedures 4L60-E - Automatic Transmission
4L60-E - AUTOMATIC TRANSMISSION
Park/Neutral Position Switch Replacement

Tools Required
- J 41364-A Neutral Position Adjustment Tool

Removal Procedure

pic 1

1. Apply the park brake.
2. Shift the transmission into neutral.
3. If equipped with four wheel drive (4WD), remove the front propeller shaft.
4. Remove the transmission control lever to manual shaft nut.
5. Remove the transmission control lever from the manual shaft.
6. Disconnect the park/neutral position (PNP) switch electrical connectors.
7. Remove the PNP switch bolts.
8. Remove the PNP switch from the manual shaft. If the PNP switch did not slide off the manual shaft, file the outer edge of the manual shaft in order to remove any burrs.

Installation Procedure

pic 2

1. Install the PNP switch to the transmission manual shaft by aligning the switch hub flats with the manual shaft flats.
2. Slide the PNP switch onto the transmission manual shaft until the switch mounting bracket contacts the mounting bosses on the transmission.

Important: If a new PNP switch is being installed, the switch will come with a positive assurance bracket. The positive assurance bracket aligns the new switch in its proper position for installation and the use of neutral position adjustment tool will not be necessary.

3. Install the PNP switch to the transmission with two bolts, finger tight.

Pic 3

4. Position the J41364-A onto the PNP switch. Ensure that the two slots on the switch where the manual shaft is inserted are lined up with the lower two tabs on the tool.

Notice: Refer to Fastener Notice in Service Precautions.

5. Rotate the tool until the upper locator pin on the tool is lined up with the slot on the top of the switch.
Tighten the bolts to 25 Nm (18 ft. Lbs.).
6. Remove the J41364-A from the PNP switch. If installing a NEW switch, remove the positive assurance bracket at this time.
7. Connect the PNP switch electrical connectors.

Pic 4

8. Install the transmission control lever to the manual shaft with the nut.
Tighten the nut to 25 Nm (18 ft. Lbs.).
9. If equipped with 4WD, install the front propeller shaft.
10. Check the PNP switch for proper operation. The engine must start in the P (Park) or N (Neutral) positions ONLY. If the proper operation of the switch can not be obtained, replace the switch.

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Let me know how things work out for you.

Take care,
Joe