guages don't work.... how to fix?

ok the first thing to do is replace the instrument voltage regulator(aka ivr). you will find it behind the instrument panel. you can pick one up from most any mustang parts supplier. that is usually the problem when all the gauges dont work. if an individual gauge doesnt work, then you start at the sending unit for that gauge. ground the wire attached to the unit with the ignition on. if the gauge reads at its highest level, then the sending unit is bad. if not the check the wiring back to the gauge.

My gas gauge problem was a leak in the float on the sending unit. This gives an empty reading because the float sinks to the bottom of the tank. A new plastic one is $4 and takes about 15 minutes to fix.