Electrical issues 97 crown vic

I have a Crown Victoria that occasionally would hesitate on starting and you would have to turn over and pump the gas a couple times check the switch checked found running off the battery cable with look like a ground but I'm not quite sure I have pulled the battery charged it it was a good battery I've been checking on tracing wires and I found what look like a cut ground I don't know but my car is dead to the world. Now while I was driving down the street one day the speedometer started jumping real bad couldn't tell how fast I was going or anything now I've had a couple electrical issues where the radio stations would jump my AC does not work and it I don't know why it only has a heater but now my car does absolutely nothing I have traced wires I checked fuses I checked relays any ideas under the sun

I've been having the gauge issue on my 2010, also my odometer is super dim. Also I have the cut ground, don't worry about that unless it's your only ground. From what I have been reading it's either the gauge cluster itself or the wire that goes to the overdrive off button on the shifter shorting out.