Tachometer troubles

[abloch]

Evening all,

So I bought an old/new solid state tach this weekend at the swap meet and I am having some issues. I've spoken with the seller and he tried to help as much as he could.

Here's the basics. 62' Fury factory wiring harness, coil, ballast resistor. MP orange box, distributor and new solid state voltage regulator. Red wire from tach goes to fuse block for keyed 12v. Black jumper to battery for ground. The green wire is supposed to go to the - of the coil or the gray/black from the orange box. I have tried these and the + side of the coil and I keep getting the same reading. "key on" and the tach reads 2000rpms. Turn on the motor and the tach runs in reverse. I even read about switching the polarity be flipping the distributor leads from the orange box and still no go.

And and all suggestions would be greatly appreciated.

Andrew

 

[SwedCharger67]

Not sure I understand what tach you have got...new/old?? Normally I think the signal in to the tach would be connected to the - side of the coil.
My trouble with erratic tach in my 67 Charger was bad grounding of the instrument cluster. You could try with a separate ground wire from the tach itself to a good battery ground connection.

 

[abloch]

it's an old tach that has been upgraded to new solid state internals. I tried another tach I had lying around the shop and it works so I am thinking the new tach is either defective or not compliant with my set up. I had the seller test it this weekend and according to his tester it works so it has to have something to do with my ignition set up. thinking about trying a tach adjuster but why spend more money to make this one work when I can get a different tach. Odd.