signal from my innovate lc2 in the ad1
common ground to chassis in the 2nd pin
and lentenfelter lnc002 5v output to the ad2 pin
So you have the ground from the LNC002 and the ground from the LC-2 connected together and to the middle pin on the FSV1...?
Are you sure they are both grounds...?
Disconnect the ground connection from chassis, use actual grounds from each device.
they both are running off the single common ground (to the same point as the lc2), they both register different voltages off this earth, and the lc2 also still works without a ground hooked up to the v1.2.
the LNC002 is earthed via the coil pack harness. do you think this will be the issue? simple as just joining the 2 earths on the centre pin of the v.12?