Hi!!

I have a -74 Charger which originally dont have a tachometer. Some time ago I bought an aftermarket tachometer for 8 cylinder engines and installed it according to the instructions. After install it works when the car is idling and running on low rpm, but as soon as I hit the throttle the needle on the tachometer goes to zero.. Anyone have an idea what may cause this problem? I can see that there is a resistor before the ignition coil.. If this resistor is not working as it should, can that cause the tachometer problem??

Best regards
Halvar,
Norway