Hi there!It may be a problem with the back up light switch itself.Here is some info for testing it.Hope this helps!Thanks

Automatic Trans:

REMOVAL, INSTALLATION & ADJUSTMENT

See Figures 1, 2 and 3

The neutral safety and reverse light switch is mounted on and actuated by the transmission select shaft which protrudes from the side of the transmission housing. It is located directly underneath the select lever and select cable assembly which is used to control the select shaft from the linkage in the passenger compartment.

The shifter select cable is attached at one end to the shift linkage by an e-ring and a cable end clip (though the center console must be removed and the manual shift linkage assembly must be unbolted and repositioned for access). But, the other end of the cable is attached to the transmission manual select lever with a threaded end that may require adjustment if any of the mechanical components in the linkage are replaced or if the lock and adjusting nuts are ever disturbed. Be careful not to touch the nuts on the select cable or it will require adjustment after the switch is replaced. If the cable is ever replaced, or the nuts are turned, then simply adjust the cable so that there is little or no play when both the manual select lever (on the transmission) and the gear select lever (on the floor the passenger compartment) are both in neutral.

1. On 4WD vehicles, make sure the transfer case is in the 2WD position.
2. Place the transmission in Neutral (N) using the gear select lever in the passenger compartment.
3. Raise support the rear of the vehicle safely using jackstands. Block the wheels to prevent the vehicle from moving.

Although you will be able to access the switch fine whether the front of the rear of the vehicle is raised, we recommend raising the rear in case you need to spin the rear driveshaft to check if the transmission is in gear or not.

Fig. 1: The neutral safety position (shift lever) switch is mounted to the side of the transmission assembly-4-speed models shown Fig. 2: Before tightening the fasteners, make sure the switch and selector lever are both in Neutral Fig. 3: On 3-speed models, switch adjustment is accomplished by checking continuity across the 2 terminals of connector C1

1. Disconnect the wiring from the neutral safety switch (4-speed models) or from the harness connector(s) located under the intake manifold (3-speed models), as applicable.
2. Remove the nut, washer and manual shift lever from the manual shift shaft on the side of the transmission housing.
3. For the 4-speed transmission, unstake the lock plate behind the manual shaft nut, then loosen the nut and remove the lock plate from the switch.
4. Remove the 1 retaining bolt and slide the neutral switch from the shift shaft.

To install:

1. If the transmission shaft was rotated, set it back into neutral. To do this, turn the select lever as far clockwise (downward) as possible. Then rotate the selector counterclockwise 3 notches and verify that the rear driveshaft will spin freely.
2. Position the switch onto the manual shaft, then install and finger-tighten the retaining bolt.
3. Install the manual shift lever on the shaft, then loosely install the washer and nut.
4. For the 3-speed models, adjust the switch as follows:
   1. Connect a ohmmeter or continuity checker between the 2 terminals of the switch C1 connector.
   2. Pivot the switch as far clockwise (downward) as possible, then slowly turn the switch counterclockwise (upward) until a click is heard and there is continuity across the 2 terminals.In this method of locating neutral you are actually placing the transmission in L, then moving it through two different detents 2 and D to reach N.
   3. While holding the switch in this position, tighten the retaining bolt to 186 inch lbs. (21 Nm) and then tighten the select lever nut to 169 inch lbs. (19 Nm).
5. For the 4-speed models, adjust the switch as follows:
   1. Verify that the transmission is in neutral by turning the driveshaft.
   2. Tighten the shift selector lever nut to 44 inch lbs. (5 Nm), then bend the claws of the lock washer over the nut.
   3. Make sure the neutral reference line and the cut-out in the neutral safety switch are both aligned, then while holding the switch in this position, tighten the retaining bolt to 115 inch lbs. (13 Nm)
6. Engage the wiring harness connector to the switch (4-speed) or to the harness located under the intake manifold (3-speed), as applicable.
7. Remove the jackstands and carefully lower the vehicle.
8. Make sure that the transmission operates properly in all positions.

INSPECTION

See Figures 4, 5, 6 and 7

The neutral safety switch is designed to keep the engine from starting in any gear, only allowing the starter to operate in Park (P) or Neutral (N). The switch also functions as the reverse light switch, but should ONLY turn these lights on in Reverse (R). To verify proper switch operation:

Fig. 4: Shift switch coupler terminal identification for early-model 4-door Sidekick (except Sport) and Tracker models equipped with 4-speed transmissions-the switch condition can be checked using the shift switch coupler Fig. 5: Use this chart to check continuity across the shift switch coupler terminals in various gear positions-early-model 4-door Sidekick (except Sport) and Tracker Fig. 6: For the late-model Sidekicks, Trackers and the Sidekick Sport, the switch connector is mounted directly to the top of the selector switch and the terminals are arranged differently than on the early-model 4-door Sidekick or Tracker Fig. 7: Use this chart to check continuity across the shift switch coupler terminals in various gear positions-late-model Sidekick, Tracker and Sidekick Sport models

1. Firmly apply the parking brake and block the drive wheels.
2. Place the gear selector lever in P, then turn the ignition switch to START and verify that the starter motor operates. Quickly turn the ignition switch to OFF.
3. Return the ignition switch to ON (with the engine NOT RUNNING) and place the gear selector lever in R, then check to make sure the reverse lights are on.
4. Place the gear selector lever in N, then turn the ignition switch to START and verify that the starter motor operates. Quickly turn the ignition switch to OFF.
5. FIRMLY apply pressure to the brake pedal and hold, then check each of the remaining gear selector positions and verify that the starter does NOT try to operate in any other position than P or N.
6. If any of the previous conditions are not met the switch should be adjusted.
7. On 4-speed models, if faulty operation cannot be corrected by adjustment, a test may be conducted to determine switch condition. To do so, disengage the wiring connector from the shift switch coupler and check continuity across the various terminals as shown in the accompanying chart. For instance, continuity should exist between terminals 5 and 6, as-well-as between 8 and 9 when the selector lever is in P.

The 4-speed shift switch coupler is usually found above the transmission housing in the transmission tunnel. Although access to it may be possible from the passenger compartment on most early 4-door models (if you remove the selector lever), it is probably easier in most cases to get at it from under the truck. To do this, trace the wires back from the switch at the side of the transmission until you can disengage the connector from the vehicle harness. For late-model Sidekicks and Trackers, along with the Sidekick Sport, the wiring connector is mounted directly on top of the switch.

1. If the switch does not pass these tests and cannot be adjusted, it must be replaced for safety reasons.

Manual Transmission:

REMOVAL & INSTALLATION

See Figure 1

For Suzuki vehicles, the manual transmission reverse light switch is usually threaded into the side or top of the transmission housing. The switch will almost always be found on the upper left side of the transmission case, just behind the bell housing. Do not confuse the switch with the 4WD switch which is usually mounted further back, on top of the transfer case (which is integral with the transmission on all but Samurai models).

Before attempting replacement, check the position of the switch, relative to the position of the transmission filler plug. If it is located higher on the transmission case then the plug, you should be able to replace the switch without losing any transmission gear oil. But if the switch is equal to or lower of the case than the plug, you should have a drain pan handy to catch any escaping fluid. In this second case, you should still be able to replace the switch without having to completely drain the fluid. The trick is to have the replacement in one hand while you unthread the old switch. Once the old switch is loose, quickly withdraw it while positioning and threading the replacement in its place. If done correctly, a minimum amount of gear oil will escape.

Fig. 1: The reverse light switch is threaded into the top or side of the transmission housing-this Sidekick/Tracker has the switch on the upper left side, just behind the bell housing

1. Disconnect the negative battery cable for safety.
2. Raise the hood and check to see if access is possible from underhood or if you will need to raise and support the vehicle for access. On most late-model Sidekick, Tracker or X-90 models, access from underhood is possible, but it is a bit of a reach.
3. If necessary for better access, block the rear wheels, then raise and support the front of the vehicle safely using jackstands.
4. Disenage the switch wiring connector.

Most Suzuki models utilize a switch whose pigtail is permanently attached to the base of the switch. On these models, follow the switch wiring back through the rubberized-plastic coated metal wiring clips to locate the harness connector. Carefully release the lock-tab and disconnect the wiring.

1. Clean the area around the switch to help prevent dirt from falling into the transmission as the switch is removed.
2. If you have decided that the switch is mounted low enough to warrant a drain pan, position it beneath the transmission.
3. Using a wrench or a suitable sensor socket (either flare-end or a deep socket with cut-outs to accommodate the switch wiring), carefully loosen and remove the switch from the transmission housing.

To install:

1. If you are reinstalling the original switch, check for an O-ring or for sealant on the threads. Replace a worn O-ring or re-coat the threads with sealant, as applicable. If you are installing a new switch, check that it is of the same design as the original. For instance, if the original used an O-ring and the replacement does not have one, either you have the wrong switch or the replacement was designed to use a bit of sealant on the threads.

WARNING DO NOT overtighten the switch, you could damage the switch or the aluminum transmission housing.TESTING

See Figures 2, 3 and 4

Fig. 2: With the transmission shifter in Reverse, check for continuity across the switch's 2 wiring terminals Fig. 3: On late-model vehicles, a harness connector is located behind the intake that you can use for testing ... Fig. 4: ... at this connector the reverse light circuit is checked between terminals 3 and 4

If the reverse lights stop working, and a voltage check shows NO POWER to the reverse light sockets when the transmission shift lever is in reverse, check the switch for proper continuity using an ohmmeter. The test can either be conducted directly across the 2 terminals on the switch wiring connector, or for Sidekick, Tracker and X-90 models, it can also be checked underhood using the harness connector at the back of the intake manifold. If the second option is taken, release the wiring from the clamp at the back of the manifold, separate the wiring and check for at terminals 3 and 4 (at one end of the 6 terminal connector).

The switch should test continuous ONLY when the transmission shift lever is in Reverse.