Very odd thing I have going on. I have a 95 Accord V6 non vtech with 125k. The rpms on the dash do what they want. They fluctuate from zero to 3 grand or so, but the motor runs fine and doesn't surge like the tach does. Makes me think its a short somewhere and I've searched the web to no avail. It doesn't affect performance but is Very annoying seeing the tach just go nuts and bounce all crazy. Appreciate any help.

 

Probably due to the ignition coil. There was a July 2001 Honda Service News article on it many years ago:

Tach Fluctuation and/or A/T
DTC P0725: Accord V6
On ’95-97 Accord V6s, when you troubleshoot a
fluctuating tachometer or A/T DTC P0725 (lockup
clutch does not engage), keep in mind the
cause could be a faulty resistor in the ignition coil.
The transmission control module (TCM) provides
electrical pulses through this resistor to drive the
tachometer.

Although a faulty resistor doesn’t affect the coil’s
ignition functions, you’ll still need to replace the
ignition coil to fix a fluctuating tachometer or A/T
DTC P0725 - the coil resistor isn’t available
separately. Order P/N 30520-P0G-A02, H/C
4598371, for the ignition coil.

 

Thanks a lot.