Crane Tach Adapter

[nismospek]

I have a 73 240Z with a Crane XR700 and Mallory Turbopower ignition coil. The tach is currently non functioning and I was wondering if anyone had any experience with the Crane Tach adapter. From the website it says that the adapter may or may not work. If it doesn't work, does anyone know what are some of the options for an aftermarket tach that fits within the dash? I have seen the autometer with the silver edge, but I didn't know if there might be some other brands out there.

Edited September 25, 2012 by nismospek

[nismospek]

The adapter info says also to make sure that it the adapter is not used with a Capacitive Discharge System. How do I find out if this is the case?

[cbaker]

Here's what I did and I have the XR700. Stock wiring for the ignition at the ballast resistor and coil is this. Black/white with a heavy plastic sheathing is 12V with key in full on position (not the start position where you have to hold the key). The green/white wire on the resistor outlet continues to join up with another gw wire that goes through the tach. This "other" gw wire you can't see. It comes out of the ignition switch and provides 12v to the coil, through the tach when the car is cranking. Out of the tach is the other black/white wire that normally goes to the coil (+) but may have the red from the XR700 there now. BW wire may be at the resistor like mine was. The only reason for the ballast resister is to drop voltage for a point system so this can be removed. Connect the black/white with no heavy sheathing to the coil (+). Connect the red from XR700 together with the green/white and the b/w with heavy plastic sheathing and you'll get your tach back. Check voltage to your coil when key is in the full on position. You don't need any adapter...at least I haven't. I was having misfiring issues and noticed that I had 2 resistors. One had the b/w with heavy plastic sheathing at one end with the gw at the other. The other resistor had the other bw wire at one end with a jumper wire to the coil (+) at the other. Anything less than 7 volts and you'll lose ignition at the 3000 rpm range.