tach signal

[optimaxtech]

Would anyone know? we have a 260 with an engine (L28) from a ZX, with carbed head installed. The distributor has electronic spark instead of points. Where should the tach signal come from? I believe currently it is still connected to the negative post on the coil, yet the tach does not function. I personally have not been to the car yet to assist my friend. Any help would be greatly appreciated

[gramercyjam]

I haven't looked into on the on the 260, but on my 73 240Z the tach signal used a current loop and two wires in the area of the coil go to the tach. One of the wires by the coil goes to the tach, one comes back from the tach and is hooked to the coil. This might help you to figure it out.

[optimaxtech]

Do you happen to know what wire connects where? I'm a little confused. They both would not be on the same post at the coil would they?

[gramercyjam]

No. I don't recall. They were all there by the coil though. Both of those wires don't hook to the same terminal of the coil. One of the wires does not even connect to the coil.

[billcapp]

The other end goes to the ballast resistor.

[gramercyjam]

I was thinking the ballast resistor too, but it might not be there anymore with an electronic ignition. When I went electronic, I left the ballast resistor there just for the junction for the two wires. the other end of the ballast resistor wasn't connected to anything.

[billcapp]

You're so right I forgot the part about the 280 engine...sorry:stupid:

[optimaxtech]

So was the ballest resistor just left there to connect the 2 wires together?

[gramercyjam]

On mine, yes. Can guarantee this is what you have. I am thinking the ignition power wire went to a connector on the ballast resistor, one tach wire went to the same connector, the other tach wire went to the positive side of the coil. There was no connection to the other side of the ballast resistor.

So the coil power path looks like battery->ign switch->ballast resistor->tach->coil. Lots of stuff (too much stuff) between the battery and the coil.

[optimaxtech]

Thanks for the info guys-really appreciate it!