I hat it. Seems logic never works here! OK tach not working but did before engine overhaul. Red wire goes to hot term when key is on, black wire goes to ground term under dash, white wire goes to dimmer side of the light switch, and green goes to the tach terminal at the disti.. All connections are tight. I did find that the red was originally connected to a full time hot terminal at the block. I have changed it. I have read installation instructions looking for any fuse locations and there are none. I did go back out there checked the fuses and found the fuse blown on the original red wire hook up. Replaced the fuse changed the red wire and it tach still does not work. Could constant bat. voltage have ruined the tach.
Is there a way to check the tach output at the disti.? I did change the disti. at rebuild. The new one had a blue cap and I had them change it to black. They took an off the shelf cap and switched out the coil. The disti. is a Moroso.