Fuel gauge

[classic volvo]

My fuel gauge is reading half way no matter how little or how much fuel I put in. Any ideas what it could be would be much appreciated

[grumpydad]

Hi
float could be stuck
take wire of sender in the boot
should read empty
earth wire should read full
if float stuck take out and fix

[classic volvo]

Thank you for your reply. Is it located in the central of the tank ?

[Burdekin]

Originally Posted by classic volvo

Thank you for your reply. Is it located in the central of the tank ?

Yes think there are two types from memory.

Does the engine temp gauge work? If not it's probably the voltage stabilizer/regulator thingy in the instrument panel as it is used for both the temp and fuel gauges. The previous owner had that issue with my car before I bought it.

[142 Guy]

It should be easy to access the sensor once you remove the masonite / hardboard tank covering that forms the floor of the trunk. As I recall the resistance range on the sender on my 1971 140 is 70 ohms (empty) to 10 ohms full. As noted by grumpydad, pulling the wire off the sender should cause the gauge to read empty. If it does, then the sender is likely faulty. You can confirm that the gauge works by connecting a 68 ohm resistor beteen the sender wire and ground (should read empty) and then a 10 ohm resistor between the sender wire and ground (should read full). If you need a new sender be sure to get he one used for you model year. Volvo used at least 3 different senders on the 140 and they do not interchange.

If the gauge appears to be faulty, do as burdekin advises and check the temperature gauge. A flakey fuel gauge and temperature gauge points towards a bad voltage stabilizer. However, it would be unusual / difficult for a stabilizer to fail in a mode where it gives a continuous 1/2 tank reading.

[classic volvo]

Thank you so much guys really appreciate all your advise. Makes owning such a lovely old Volvo much more enjoyable 👍