Test my Tach Question....

[Morris'_Mopars]

I have factory ralley gauges in my 71 barracuda. The tach currently does not work. How can I check to see if the tach is any good???

[Grec]

Is it currently disconnected? It's a pretty simple setup... the line from the tach runs straight to, I believe, the negative post on the ignition coil.

I finally got around to hooking mine up a couple weeks ago, and voila... it works. :-)

There should be a single line running from the dash, through a rubber grommet in the firewall. General area of behind the clutch pedal in a manual. (Mine is a '73 so your setup may be a little different)

Not sure if the gauge cluster needs to be powered for the tach to work, though...

[MEK-Dangerfield]

I don't know of a real good way to test it, other than taking it out of the car. There is a long screw where 12 volts will be supplied. There is a tab to get the "-" signal from your ignition coil. I just hook it up under my hood. I run wires to my coil and ballast resistor for power, then I take one of the screws out of the question, and run a ground wire to anyplace handy. A valve cover bolt for instance. For what it's worth, if this is the original tach, it went to heaven long ago. It is common for them to die.

[ShelbyDogg]

You migth want to upgrade it with the R-T-engineering solid state tach board anyway.  My stock 8 grand tach displays 3000 rpm, when my computer shows 2100 RPM.  Which one would you trust?