OK, so I AM looking at it....and it's a multi-wire thing

RE: The 240 n/a engines:

The Bently manual under "Instriments: Temperature and Fuel Guage", p 380-3 (don't know about Haynes) says to ground this connector, turn key to "ON" position and check that the needle moves to the top of the guage . If not, the guage or its wirin is bad.

If the guage operates correctly when the wire is grounded, the sensor is most likly faulty.

You can also check the accuracy of the guage by connecting a 68 ohm resistor (Volvo p/n 999 5825-1) between the sensor connector and ground. With ignition key on, guage should move up to the 3/4 position. If not, replace the guage.

I'll try something similar on mine.

At the bone yard today I tool apart a 740 instrument cluster to pull off a spare temp guage.

According to Haynes "Fault Finding: Electrical System" in the back of the book (UK version), p. REF 18, the fuel or temp guage give no reading r\because:

Faullty insrument voltage stabilizer
Faulty guage sender unit
Wiring open circuit
Faulty guage

Guess I should have grabbed the other items first....

And I forgot to take even a single light bulb!!!
--
"Can't understand why people abort Volvos, either"