Fuel gauge not responding - I suspect a wiring fault :(

[stevo]

So, suddenly, the fuel gauge stopped responding. Then it started again

But now its stopped again

So, thanks to this forum, I read the manual - this goes against anything I have ever learnt

Done the combination meter test, and the gauge sweeps empty to full nicely, so that rules out the meter.

To the sender, I thought, lets test that. The inspection hatch screws are made of cheese - soft goats cheese, and splayed the heads as soon as I got my screwdriver out. So, out with the drill and chisel, and off the screws came....

I can't get the sender itself out, as the rear two bolts are just out of line with the inspection hole, meaning that you can't get good purchase, especially as they are rounded off

Back to the manual, and test the resistance of the float. I suspect I have about half a tank, so resistance at 70 ohms suggests just over half. 30 quid into the tank, and resistance drops to somewhere between 15 and 30 ohms.
I'd say the sender is working

So, a wiring fault? The loom runs from the sender, across the back, and up the passenger side - I can't wait to start stripping that

 

[solarman216]

you have done very well so far, keep at it, you will get there, Rick

 

[stevo]

cheers fella - next step is to have a look at the connectors where the rear harness joins the main harness on the passenger side behind the bumper.

fingers crossed!

 

[geoffdown]

cheers fella - next step is to have a look at the connectors where the rear harness joins the main harness on the passenger side behind the bumper.

fingers crossed!

just to throw a spanner in the works it could be the dash as some of the early 3lt had doggie dashes

 

[stevo]

just to throw a spanner in the works it could be the dash as some of the early 3lt had doggie dashes

The gauge works, as I did the diagnostic test that sweeps the needles from empty to full and all was okay

 

[stevo]

So, testing the float - I have a full tank, so should have a very low resistance across the terminals of the sensor.Using my trusty multimeter, I get 7 ohms, which is correct.

The sweep test on the combination meter (posh name for dash) shows that the needle is capable of a full sweep.

Continuity test on the harness gives me a signal, but thats inconclusive really as I don't know how far the circuit goes before it would be completed.

Multimeter set to voltage and connected to the pins in the harness for the sender unit gives me 2 volts. I'd have expected more....

I also get an ampage reading, so I'm happy I have power, and earth. Whether the voltage is enough, I don't know.

The gauge reacts the same regardless of whether its connected or not - ign on and it rises slightly to the red, then drops again, about halfway to the stop.

I reckon its dash cluster out now, but what is there to see? :nenau probably nothing

 

[stevo]

Dash cluster out..... nothing to see here :nenau


Although with the magnifying glass, the top left joint looked pitted. I'm assuming the connectors in question are the 4 around the circle.

Out with the soldering iron and it looked a bit better, but no change when plugged back in......

Interestingly, I couldn't get a reading for voltage from the connector to the dash cluster. would have expected the same voltage as at the sender (2v)