Speedometer/Tachometer goofiness

I have a 93 Honda Civic (Kelly). Driving on the Highway today and the Speedometer and Tachometer went down to zero and bounced around for a few seconds. It soon returned to normal. It did this a few times. I noticed once that the clock also dimmed a little. The car may have also lost a little power one time when this happened. Any suggestions on what this could be? THANKS!!!

Start by checking the cable connections at the battery. Then check the ground connections, including engine to chassis ground. You might want to have the alternator and the battery tested, too.

Thanks!!! I have checked all the connections. I am getting the altenator and battery tested also. Havent heard back yet. Another thing I heard it might be is the ignition switch and a slipping clutch. Do you think those may be it???

My mechanic said he saw wires ‘arcing’ What does this mean? How much would this cost to fix? Would this probably fix the problem? He also recommended a full tune-up. Would this help?