1997 Legacy GT 5MT, Weird speedo behaviour

[0ny1x]

Speedo oscillates while driving. Reads anywhere from 0-30 while sitting still and jump up and down while rolling slowly. Cruise control still works, no CEL, speed read from a scanner is correct. When the turn signal is on the needle slowly bounces up and down maybe 1km/h in sync with the indicator. Odometer doesn't go up except every now and then the trip odometer goes up by like 0.1 Km. Car is a 1997 Subaru Legacy 2.5GT 5spd Sedan. Speedo issue suddenly started after hitting a bump at slow speed.

[doublechaz]

I would start with the ground strap from the trans to the chassis and proceed on to the ground from the intake and block to chassis and finish up with the grounds for the cluster in the dash.

 

I say that because of the jumping in time with the blinker and the video appeared to have the needle jumping in time with the engine rpm.

 

Do you have the Factory Service Manual?   If not, find it on here and download it.  I think there are some pretty good referennces to it in the thread about someone's vacation pictures.

[0ny1x]

Alright thanks I'll look into those.

[wtdash]

Since your scanner works and cruise, this likely doesn't apply, and I don't know if your Canadian/ European (?) model is the same (I see KM/h speedo), but the USDM/USA models had a speed sensor (VS1?) on the passenger-side of transmission tunnel. These failed where the tip goes into the 'gear' in the trans.  There are pics online.

Also, if there any other undiagnosed electric gremlins, I'd clean your battery terminals.