NEW MEMBER,with an old 73 240z

[CHARLIE'S Z]

hi. I installed a crane cam xr3000 optically triggered ingition system with

the fire ball coil. (the system works great)

my problem is that the tachometer only works when cranking the engine.

any help?

[EScanlon]

You have connected the Green/White AND one of the B/W wires that used to run to the resistor to the same post on the coil. (The original circuitry had only ONE B/W wire going to the coil, and one B/W and one Green/White wire going to the resistor.)

Since you do NOT need the resistor any longer (since you no longer use points), you DO need to maintain the circuitry the resistor provided. That is a necessary part of the tachometer circuitry, without it you'll only have a tach reading when the starter is engaged.

Typically just connect the B/W and the G/W wire that used to connect to the resistor to each other and maintain the one B/W wire that went to the + post on the coil AT the coil.

There may be a small variation with the Crane system, but the car's circuitry needs to be accomodated as well.

Hopefully this will help get you started. Now that someone has ventured a response the other guys can nit-pick this apart and you'll have a solution.

FWIW

E

[CHARLIE'S Z]

i have tryed EScanlon advice. dosn't work.

hooking up a tach tool to negative side of coil works.

hooking up postive to postive side of orignal coil wire kills the

crane ingition system when a jumper is used in place of the

ballast resistor, no tach with out it