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Have an 85 150 with inline 6. Oil gauge, temp gauge don't work and fuel gauge only somewhat. Could a bad ground cause a problem? Or just a bunch of bad sensors?
Have you checked the fuses?
Replace if needed. I'd check them with a meter if you have one. No often but sometimes they can look ok but still be blown.
Are there any other gauges that do work like voltmeter or tachometer?
When you say the fuel gauge works "somewhat" do you mean it always reads full, empty, or does it float?
Again if you have a meter you could test your circuits for power or resistance or check for open circuits (short in system)
Do the dash warning lights come on when you first turn the key to run? The battery light, check engine light, oil pres warning, and any other warning light should come on briefly when the key is turned to run position.
If no, check the harness that plugs into the back of the cluster.
One the back of the cluster there's a small silver colored box the bolts on to the cluster and connects to the printed circuit with what resembles a 9 volt battery connection. That silver colored box is the instrument voltage regulator. It controls provides steady voltage to the gauge circuits. It fails quite often. If all three gauges are not working, chances are that's your problem.