Dash guage question

[Zonaman]

I'd like to install a small tachometer in the vaccum guage slot in the dash. The hole cutter lines up nice with the dash assembled for a nice clean cut. Is there anything but plastic in the vaccum slot- can I cut right through?

Thanks.

[Zonaman]

OK. There was nothing but dash metal (instead of plastic) in the way so I cut into it. Didn't hit the pritnted circuit for the dash or anything. The guage went right in. The tach works fine but now the ammeter quit. It's pegged on "C" on or off. Maybe it was gone and didn't notice it till I put in the tach- A conicidence?

Just to be sure, I'd like to ask if wiring the tach could have taken out the ammeter? I've included a wiring diagram for the tach as well as a diagram of where it wired it in to the fuse block. In case my wiring screwed it, someone might be able to see where it went wrong.

I tested the charging system: 12 volts on battery engine stopped, 14.5 running. I've converted to pointless ingnition and took my tach feed off the post on the distributer (Accel 140003) Everything seems to be fine otherwise. Should I just skip the ammeter and go with a volt meter?

Thank you.