Some instrument panel gauges are not working, what could be the issue?
1996 - Peterbilt 379
The only gauges working are: manifold pressure, oil pressure, water temperature, and air pressure.
Gauges not working are: alternator, fuel guage, speedometer, pyrometer, tacometer, and engine oil temperature.
I have checked the accessory relay and it seems to be working fine (according to test light). What else might I be able to check to get these gauges working?
The gauges have ground but no power.
Is this a worthwhile discussion?