Flakey tach

[the_Journeyman]

2000 900SS, 13,000 miles

My tach acts a bit flakey from time to time on my 900SS.  Any ideas what causes this?  I don't even know if it's a cable or electronic unit.  For instance, this morning, when I cranked, it stayed a 0 for a 15-20 seconds.  Then suddenly jumped to indicate 1500RPM (about right, I was warming up with fast-idle partially pulled) and worked normally for a few minutes.  It also will just randomly change by about 1000RPM when I'm just cruising along and keeping a steady throttle hand.  Doesn't really hurt anything, but just curious about where to go poking around next time I'm doing a little service work ~

JM

[ducpainter]

2000 900SS, 13,000 miles

My tach acts a bit flakey from time to time on my 900SS.  Any ideas what causes this?  I don't even know if it's a cable or electronic unit.  For instance, this morning, when I cranked, it stayed a 0 for a 15-20 seconds.  Then suddenly jumped to indicate 1500RPM (about right, I was warming up with fast-idle partially pulled) and worked normally for a few minutes.  It also will just randomly change by about 1000RPM when I'm just cruising along and keeping a steady throttle hand.  Doesn't really hurt anything, but just curious about where to go poking around next time I'm doing a little service work ~

JM

It's electronic and is fed off the ecu.

Check the connectors on the bottom side of the gauge unit...

worth a shot.

[the_Journeyman]

Thanks dp!  I'll have a look see, sound reasonably simple 

JM