Volvo 240 Instrument Cluster Wiring Connection for Engine Swap

If you want to keep using the original instrument cluster, and thus the check engine light, oil pressure, tachometer, etc., during an engine swap, you will need to adapt the wiring. The original wiring that went to the B20, B230, or another engine is no longer connected. With the information in this article, you can retain most of the instrument cluster functionalities, which is cost-effective and, of course, improves the aesthetics.

Below you will find various diagrams with their corresponding pin-outs, so you know exactly which engine wires need to be connected to the respective instrument cluster wires.

If you want to convert the odometer to a GPS model, you can use the LCM GPS Speedo plates. These allow you to easily install a GPS speedometer in the original Volvo 240 cluster.

Volvo 240 1st Gen (1974-1980)

31. This is the 12-pin connector on the back of the instrument cluster31. This is the 12-pin connector on the back of the instrument cluster
    31.1. Yellow – Not used
    31.2. Blue/Yellow – Defective light indicator (Ground)
    31.3. White/Red – High beam indicator (+)
    31.4. Red – Alternator indicator light (Ground) (from 31.9)
    This connection is important for an engine swap; without the alternator light, an alternator will not be activated.
    31.5. Grey – Brake function indicator light (Ground)
    31.6. Blue – Right turn signal indicator light (+)
    31.7. Not used
    31.8. Green – Right turn signal indicator light (+)
    31.9. Red – Alternator indicator light, comes from alternator D+ (goes to 31.4)
    This also needs to be connected again.
    31.10. Yellow – Coolant temperature signal.
    The easiest way is to use the Volvo coolant sensor in the new engine and connect it to this cable. All you need to do is tap the correct thread size and use the original Volvo sensor.
    31.11. Black – Oil pressure sensor signal
    Check if the old and new sensors have the same function. Usually, this is an on/off sensor, and there is a good chance that the sensor on the new engine can be used.
    31.12. Yellow – Overdrive indicator light (+) Comes from the switch
32. This is the 5-pin connector on the back of the instrument cluster32.1. Brown – Handbrake indicator light (ground)
    32.2. Blue/Red – 12V from fuse 5 (1980 is fuse 13)
    32.3. Black – Choke indicator light (+)
    32.4. Grey – Fuel level sensor signal

34. This is the 2-pin connector on the back of the instrument cluster
    34.1. Red – EGR Switch signal (ground)
    34.2. Red – EGR Light (ground)

Volvo 240 (1984-1987 VDO)

31. This is the 12-pin connector on the back of the instrument cluster
    31.1. Grey – Brake function indicator light (ground)
    31.2. Yellow – Coolant temperature signal.
    The easiest way is to use the Volvo coolant sensor in the new engine and connect it to this cable. All you need to do is tap the correct thread size.
    31.3. White/Red – High beam indicator (+)
    31.4. Yellow – Overdrive indicator light (+) Comes from the switch.
    31.5. Black – OP light (Ground)
    31.6. Red – A/C Relay
    31.7. Blue – Right turn signal indicator light (+)
    31.8. Green – Left turn signal indicator light (+)<
    31.9. White – 12v from fuse 8 goes to the clock and tachometer
    31.10. Brown – 12v from the lights
    31.11. Red – Alternator indicator light, comes from alternator D+ (ground)
    This also needs to be reconnected to the alternator of the new engine.
    31.12. Blue/Yellow – Light check warning light (ground)
32. This is the 5-pin connector on the back of the instrument cluster
    32.1. Grey – Fuel level sensor signal
    32.2. Brown – Handbrake indicator light (ground)
    32.3. Black or Blue – Turbo warning indicator light (ground) (not used in 1987)
    32.4. Black – Ground

34. This is the 1-pin connector on the back of the instrument cluster for the Overdrive when it is deactivated

    1987 Extras

    200. Shift indicator

233.1 Blue – Speed sensor from the differential

233.2 Black – Speed sensor from the differential

233.3 Red Black – 12V run position from the ignition