Hi !

On my 1978 244DL, both fuel and temp gauges are far too high. I know that
fuel is about 1/4th and it reads 1/2. Temperature is very close to the red
zone and I know that the thermostat is new and that the engine does not get
too hot.

I already changed the voltage regulator, anyone an idea where to investigate
?

Thanks in advance !

Probably the easiest thing is to go to a wrecking yard and get a couple
of replacement gauges from an instrument cluster.

Replace them with yours and see if the problem persists.

If it does: the fuel gauge may be erroneous due to a failing in tank
measuring device.

Hi,

Thanks for the answer !

I bought a couple of instruments clusters on ebay. Amazingly the model
changed all 3 I got were not compatible. I switched a temp gauge and a fuel
gauge and the problem remains... What struggles me is that it really seems
that both gauges are indicating 2x the value...


<zencraps (AT) comcast (DOT) net> wrote

ViSu wrote:
Bad ground?

There is a module called a temperature compensator. It may be the same
thing that you called the voltage regulator. It's a small printed circuit
board about the length of your pinky finger. It plugs into the back of the
instrument cluster. It handles voltage to these two adjacent gauges.

If this does not describe what you called the voltage regulator, then I
would suspect this module. Even if it is, it is easy to get defective
compensator, or to damage it with handling with your fingers exposing it to
oils and contaminants.

I think the brickboard has an article on bypassing this module. Several
owners have found that it is a weak link.


"ViSu" <visu (AT) telenet (DOT) be> wrote

Thanks, that's a good one.

Having bought a couple of clusters on ebay and already possessing one, I
swapped them all, in vain.

But thanks for the feedback !




"Pat Quadlander" <pquadlander (AT) comcast (DOT) net> wrote

If you did not get the gauges fixed yet here is the answer.
Your Volvo has a voltaged stablizer on the back of the instrument cluster.
It is a small rectangular box that has 3 male spade connectors.
Unplug it and install a new stablizer.
The stablizer reduces the voltage to 10 volts for the temp and fuel gauge
only.
The lower voltage is used so the gauges do not vary.
The gauges are 10 volt gauges.
Higher voltage higher readings.
In 1981-1985 volvo switched to a solid state stablizer for 240's.
In 1986 on, Volvo used the comp board.
BD

"ViSu" <visu (AT) telenet (DOT) be> wrote