I took my battery out to fix a hardline hose on my wiper motor that cracked.
After putting the battery back in my speedometer was pegged out past 100mph!
Looked online at how to fix ……Ha Ha! Not pulling dash apart….
and thought all I did was take the cable off!
well I just had someone watch the gauge while I wiggled the
NEGATIVE battery cable (Alarm was going off and on) until it went back to 0mph!
I would try this FIRST! …… It CAN be that easy!