Below is a series of steps that may help fix one of the most common rear light faults that affect Volvo 240's.

If the switch at the gear selector is not faulty, next test for electrical current at the rear left tail light, where the wiring loom surfaces. The two black wires going into the white plastic block connector should carry current to the reverse lights. Often you will get current before the block connector, but no current to the circuit and bulb after the white block connector. A perfect fix would be to replace the circuit backing as it gets damaged at the block connection over time. For a cheap alternative connect a wire from the circuit at the bottom of the bulb, this is “positive” or carries current, and connect it directly to the black wire. Then connect a wire from the circuit at the top of the bulb, the earth, to a good earth. Doing this you bypass the plastic block connector and will fix the reverse light.
If the above fix does not work, try some simple fault finding tips below.
In the picture below these 3 wires connect to the gear selector switch, triangle shaped. When the car is running and in PARK the yellow wire will have current, the black wire will not. When the car is in REVERSE the yellow and black wire will have current.

Below picture: this is the reverse side of the gear selector switch. To remove this from the gear shift “pit” put the selector into FIRST, undo the two philips head screws and gently lift out. On the opposite side there is a tin plate, this can be removed by gently bending back the four tabs.


Below picture: Once the tin cover is removed you will see the white plastic “arm” that slides across the contacts. When you lift this off there is a small brass tab that connects two separate plates to allow current to travel between the separate plates when it slides from one position to another. Cleaning off built up grime will help.

Below picture: in this picture the “arm” is in the REVERSE position, allowing current to travel between two of the brass plates. At this point use a continuity tester to make sure current can travel between the yellow and black wires. If you use a tester, select the resistance setting. A reading of zeros means the switch is working. A reading of “1” means current cannot travel through the connection.


If I have missed anything please let me know. This fix worked great for me and saved me alot of money as I did not need an auto electrician.