One of my friends recently got a 1998 Subaru Legacy L wagon, and the speedometer in it decided to start tweaking out, and within 20 minutes it stoped working all together. I noticed it's electronic. Has a little black thing in place on the tranny where the cable would normally go with 2 wires comming out of it. Do these typically fail, or is this probably another problem dealing with the computer?

Sometime the VSS on the trany goes, but these have problems with the speedo head. If the CEL is not on and the cruise still works the VSS is sending the signal out. Its most likely the speedo or the connections.

 

Try pulling the gauge cluster and remove the screws holding the speedo in. Clean the contact and replace the screw. Put it back in and see if it works. I've fixed a few this way.

 

If you need a new gauge cluster let me know I have a spare.

The cruise control isn't working, and the check engine light came on in result, so this is the sensor on the tranny then right?

Could be, or could be the wires feeding the info to the ECU. Make sure all the grounds are good.

the tranny sensor is $104.00 not including tax... and the thing is the size of my cell phone if not smaller... We decided we better check the ecu codes at a shop first before deciding to actually buy the part. Thanks for the help! Carter Subaru is telling me that the check engine light will still come on if the speedometer dies on the instrument panel side... *shrugs*