Speedo not working, why???

[S13_RB25]

Hey i guys i recently bought a 89 240sx hb. When i got it home i drove it the next day and saw that the speedometer was dead at 0mph when i know i was doing like 40ish, but i parked the car and looked under it. I saw a wire hanging with a plug connected and the wires look like they might of hit my drive and probably got pulled. But before even this the speedometer was showing 75mph when i was doing 50mph. Could that also be related to the wire being somewhat broken and messing up the readings and then its hanging and now the speedo isn't working??? Should i order a new speed sensor or a new lower harness?? But i am going to take a look under the car tomo, cause it rained all day today and yesterday... Thanks in advance for any advice and help...

[Gabes13]

Your speedo sensor might be bad.
I don't think it would work at all if the wire were cut.

[S13_RB25]

Your speedo sensor might be bad.
I don't think it would work at all if the wire were cut.

well it's not working, after the day I bought it I parked it in the driveway. But on the way on to the driveway I think the plug or the wires hit the ground and got dragged and broke either the wires or the plug. It looks as if it's the wires though...