24 = VSS, vehicle Speed sensor.
unsafe-at-any-speed?
this reed switch is not clicking.
is your speedo operational , showing correct speed and not jumping around like crazy.
no, then cable or speedo is bad.
yes, ok, then you need to clean A1 and A2 contacts on the speedo.
if cleaning them dont fix it ,then a new vss is required,(radio shack has em)
ok.
the vss bad will wreck MPG. and other things.