Rev counter conversion

[Iain.]

Have set about re-wiring the CB-1 dash.

Everythings all good apart from the rev counter, it takes its power and earth from the CB-1 loom, and the pulse signal wire from the CBR loom. CBR rev counter operated fine, CB-1 rev counter worked fine when connected to CB-1 engine.

Any suggestions as to why this isn't working?

NC23 CBR400 Tri-Arm loom, F reg CB-1 clocks.