How to Test a Volvo 940 Fuel Relay

Volvo manufactured the 940 series from 1991 to 1998 to contain two fuel relays. These are the fuel pump relay and the fuel injection relay. Both relays have the same basic connections which are two wires to the coil and two wires to the contacts. The coil moves the contacts to make a connection. Use the same procedure to test either Volvo 940 fuel relay. Consult your owner's or maintenance manual for relay locations and exact pin numbers for your particular year and relay. You need to know how to operate a multimeter.

Things You'll Need

  • Multimeter
  • 2 Electronic test leads with alligator clips
  • Pull the relay out of its socket.

  • Set up the multimeter to read ohms and touch the tips of the test leads together. The meter should show zero ohms.

  • Touch the meter leads to the coil pins on the relay. The meter should show from 50 to 120 ohms. If it reads zero or infinite ohms, the coil is either shorted or open and the relay is bad.

  • Touch the meter leads to the two contacts of the relay that make connection when the relay closes. The meter should show an open circuit or infinite ohms. If it reads a short or zero ohms, the contacts are shorted and the relay is bad.

  • Connect one end of each of the test leads to the coil contacts of the relay. Connect the other end of one of the leads to chassis ground and the other to the positive battery lead of the Volvo. You should hear and feel the relay click.

  • Touch the meter leads again to the contacts that close. They should now read zero ohms or a direct short. If not, the relay is bad.