Where is the Backup Light Switch Located?

Where is the Backup Light Switch Located? In automobiles, having a reverse light is an option, not an obligation. You can install one reverse light if you want. 

Getting it fitted on your vehicle is unnecessary if you don’t want one. However, if you get a reverse light fitted in your vehicle, you must comply with the local regulations. 

In Europe, vehicles can have a reverse light on the side of the driver, while it should be on the right side in Australia. 

You can use fog lamps on the opposite side. In the USA, the vehicle has two reverse light globes in their vehicles.

Either way, having a backlight is a safety measure for pedestrians; if there is any failure, rectify it immediately.

The reverse or backup light circuit is very simple, with one or two lights at the rear side, operated by a switch. 

Mostly, any issue with the lights arises due to the backlight switch’s failure.

Where is the backup light switch located?

Let’s get into these details in the following article.

Table of Contents

What is a reverse/backup light switch?

A switch, either open or closed, controls a circuit. The current does not pass to the load in an open switch, while a closed switch has a continuous current flow. 

The connection of the backup light switch to the gear selector mechanism is based on the transmission. 

When you put the gear into reverse mode, the switch completes the circuit, and the reverse lights turn on.

A reverse light circuit can be used for things other than turning on the reverse globe when you put the reverse gear in a manual transmission vehicle and the “R” range in an automatic transmission. 

In the manual transmission vehicle, an ON/OFF switch activates physically when you move the gear to reverse mode. 

On the other hand, in automatic transmission vehicles, the backup light switch is integrated into the range selector switch. 

Despite the complex nature of the range selector switch, the working of the reverse switch remains the same in both automatic and manual transmission

Most cars have this switch on the gearbox and operate automatically with the reverse gear selection. 

However, if your vehicle has aftermarket lights, you can mount them on the dashboard.

Automatic gear shift

How to identify whether the problem is with the backup light switch?

You can trace any issues in the backup light system back to any of the elements in the path of the electrical circuit sending current to your bulb.

Blown bulb:

First, connect the bulb to the battery’s two terminals using a short wire after taking it out. The lighting of the bulb indicates that the fault is not in the bulb. 

Before reinstalling, check the wiring terminals and the bulb holder; clean the dust and corrosion with dry/wet paper.

Fuses:

If both the lights go simultaneously, there is a high possibility that a fuse has blown. Sometimes, the fuse, which protects the reverse lights, also protects other accessories. 

Check if all the others are working or not. If not, the problem is a fuse. Change the fuse and recheck the circuit.

If the fuse blows away again while testing, it can be a short circuit. Call an automobile electrician to find out the issue.

If other accessories connected with the same fuse work, you must test the reverse light circuit with a testing lamp.

Checking current:

Switch on the ignition. To prevent overheating, take out the feed wire. Select the “R or Reverse” position in the automatic transmission and reverse gear in the manual transmission.

Ground the testing lamp and connect the live wire to the bulb holder. The lighting up of the bulb explains that the bulb is getting the current. 

However, bulbs can have faults if they have their own ground lead.

Use a short wire between the holder’s body to check the earth at any point on the car’s body. Now, recheck the bulb; renew the earth’s wire if it lights up.

Wiring check:

If there is no current in the circuit during the test lamp check, you must check the entire wiring. 

For this, you must know the wiring route and color of the reverse light wires. 

You must probe the wire into the main circuit carefully. 

Sometimes, it disappears, and in such cases, splice in a new wire to rectify the problem.

Switch test:

If the wiring has no current, check the switch in the gearbox. There are two terminals in a switch in a manual vehicle, while in an automatic car, there are four. 

Two of the four are meant for the inhibitor circuit and must be disturbed only when adjusting the switch. Refer to the vehicle manual to determine the correct testing terminals.

  • The switch testing becomes easier if you put the car on jack stands.
  • Turn on the ignition and put the car in the reverse gear.
  • Connect the test lamp and the ground and probe both terminals individually.
  • The lamp’s illumination in both terminals indicates a  fault in the wiring from the switch to the lights.
  • Examine the wiring from the switch to the fuse if the test lamp does not light up.
  • If the test lamp illuminates on any one of the terminals, it indicates that the switch needs some adjustment. 
  • Disconnect the wiring if you need to replace the reverse light switch. Unscrew the reverse light switch or release the lock nut if there is one. Adjust the switch after replacing it in backward order.

Adjust the switch:

First, connect the circuit tester to both terminals to adjust to the lock nut-type switch. Select the back gear and release the locknut. Start screwing the switch till the tester light turns ON. 

For adjusting other switches, you need to unscrew the switch entirely and add/remove shims. In such cases, the correct setting is when light illuminates when the switch remains in fully tight condition. 

In automatic vehicles, you will find adjustable switches. You can follow the below-mentioned procedure to adjust them, but it is always better to refer to the vehicle manual for the correct procedure. 

First, identify the four terminals and the switch wires connected to them. Once found, disconnect them. Put the gear in the driving position and release the locknut. Unscrew the backup light switch with a couple of turns from the gearbox. 

Now, take a tester that has its own supply of power. Connect it to the two terminals of the reverse light. Start screwing the switch until the backup light turns off. Make a mark at this position with some paint. 

The next step is to connect the tester to the two inhibitor terminals. Start screwing the switch towards the inner side until the tester lights turn ON.

 Make a mark at this position also in line with the earlier mark. Now start screwing the switch until this mark is halfway between the two other gearbox marks. 

Car electric repair

Car electric repair

Adding reversing lights:

If your vehicle has no company-fitted reverse lights, it can be fitted with an aftermarket set. 

Some vehicles have all the wiring; you only need to fit the gearbox switch and lights and connect the wiring. 

You need to check with the dealer or the manual to know, if possible. 

If the wiring does not exist, you must manually turn the switch ON/OFF on the dashboard. 

Also, a warning light must remind you when the reverse lights are ON. It’s not right legally to move forward with a backup light on. 

Fitting a light:

Clamp-on type:

First, look for a suitable place on the bumper. Fit the clamp on the bumper, keeping the protective rubber pad in place. 

Now, fix the light unit on the clamp. For clamp-on lights, you need to put a separate earth wire. 

You can either join this wire to the existing bolt or fit a new bolt by drilling and joining a wire to it. 

A Bolt-on type:

Finalize the fitting position of the backup light unit. Cover this area with a masking tape. Mark the holes for the bolts on the tape using a pen.

 Drill the holes and bolt the lights firmly on the bumper. When drilling, put Vaseline on the drilled edges to prevent corrosion. 

Flush mounted type:

Put the base of the reverse light unit on the vehicle body and mark the screw position. Drill out the holes and secure the light base to the body firmly.

 Screw the light lens on the base plate and feed the wire inside the body through the holes.

Fit gearbox switch:

Find out the gearbox position with the help of the manual. You can find it covered with a blanking plug or a small plate. Unscrew the plug and fit the switch there. 

Wiring relays:

Whether you need a relay in a circuit depends on the power required by the aux backup lights. You can do without a relay if it is less than 60 watts. 

However, if the aux lights are more than 60 watts, you may need a regular Bosch relay. 

Auto relay wiring

Auto relay wiring

Wiring switches:

Disconnect the battery and connect a wire between the gearbox switch and the ignition-controlled feed. 

Fix an in-line fuse. Now, run a wire between the vacant switch terminal and reversing lights by running it under the carpets. 

Wiring the lights:

Drill a hole to fit a grommet and pass the feed wire through the car body. Connect the wire to the reverse light unit. 

If you use two lights, join an extra wire into the feed wire from the gearbox switch. Connect this second reverse light unit. Connect the battery and test the circuit. 

5-pin socket wiring harness

5-pin socket wiring harness

Conclusion:

If you have the right components, you can easily add an aftermarket reverse or backup light to your vehicle. The most important is the wiring for best results and easy installation.

For any automobile wiring harnesses and cable assemblies, contact Cloom. We are a leader in manufacturing various cable assemblies and harnesses for different applications.