I have a 1990 Accord DX.. The speedometer needle is wanting to hop around then sometimes not work at all. Any ideas of what could be wrong??

 

VSS AKA Vehicle Speed Sensor is the first thing I would look at.

 

if the vss isnt the problem try going to a junkyard and jjust getting the speedometer motor out of a 4th gen and install it. my old car (a crappy 88 ford mustang) used to do the same damn thing. soon as i hit 65 (if it was even going 65) it would jus drop and made it seem like i was going 100 miles an hour, then when i get to the speed of about 35 or so it would come back and start actually telling me how fast i really was going. never trust a ford, ugh!