Mallory Unilite Distributor Wiring

[rocketdog]

I'm installing a Mallory Unilite dizzy w/ mechanical advance to complement my new triple Webers. My OEM dizzy had two wires (blue and black) that apparently went to the electronic ignition module. The wiring diagram with the Unilite has the wires going directly to the coil/ballast. I'm having a brain fart here and but I think that the new dizzy doesn't need the OEM ignition module since it has it already built in and that I would wire it according to the diagram and abandon the old wiring. But.....the OEM ignition module affects other stuff too (tach, etc) and somehow needs to be wired in. I've search this site and others and cannot find an answer. Most searches come up with ADDING electronic ignition to a 240 w/points.

[steve91tt]

This is the wiring configuration that I am using with my Unilite.

You are correct, you don't need the OEM ignition module. I also had to purchase a Mallory adaptor to get my tach to work but that's on a 240Z. I can't speak for the later Z's.

[Carl Beck]

I did not need an adaptor - I used two ballets resistors on my 72 240Z. Don't know what else you would need for a 280Z.

See: http://www.zhome.com/ZCMnL/tech/MalloryDist.htm

FWIW,

Carl B.

[Zed Head]

Looks like you're doing a late 260Z, with the first electronic ignition? The wiring would be like a 280Z, I would guess, if the tachometer is the 280Z type. On my 76 280Z I disconnected the ignition module inside the car completely, but reconnected the blue wire from the ballast resistor to the negative post of the coil (that's what it is effectively connected to, but at the ballast resistor instead of the coil). The blue wire (I'm assuming yours is blue too) runs to the ECU and the tachometer on my car from the negative side of the coil, bypassing the ignition module on the way. It's a branched circuit.

This was for a GM HEI module, but should apply in your case also, since you're replacing the OEM module with a different one.

Edit - I had written tach and tachometer instead of ECU and tachometer. Of course, your 260Z doesn't have an ECU.

Edited May 18, 2012 by Zed Head

[steve91tt]

I did not need an adaptor - I used two ballets resistors on my 72 240Z. Don't know what else you would need for a 280Z.

See: http://www.zhome.com/ZCMnL/tech/MalloryDist.htm

FWIW,

Carl B.

Sorry, you are right. The tach adaptor was needed for my MSD box...not my distributor.

[rocketdog]

Thanks for the feedback. The blue wire already is connected to the (-) side of coil. I followed it on the wiring diagram and as you say it is a branched circuit with one going to the ignition module and one to the tach, so I'll leave that in place. I haven't yet started up the engine with the new Webers and go through the tuning and synchronizing. I will leave the OEM dizzy on for now as don't need to potentially troubleshoot two major changes.

[rocketdog]

No spark! Fired up the Webers with the OEM dizzy and engine ran fine with the usual carb tuning and tweaky stuff. Put in the new Mallory dizzy w/ new spark plug wires. Connected according to diagram: Brown=ground, Green to (-) on coil, Red to ignition side of ballast. Left all other wires connected as found. There is no spark going from coil to dizzy. Suggestions?

[rocketdog]

Continuing: With ignition ON I am getting 12V to the coil and (+) ballast and about 6V through the ballast.

[rocketdog]

A PM from Mike W suggested removng the blue wire from the coil as that what worked for his late 260. Tried it with no success. Usually with electrical stuff like this it's something simple/stupid. I'm scouring the FSM electrical schematics to see if anything shows up.

[Zed Head]

Do you get 12V to coil + with the key at Start? There are two power supplies to the coil +, one bypasses the resistor during starting and the other goes through the resistor with key on. Maybe you've left the Start circuit to the coil disconnected. When you turn the key to Start the power to one circuit turns off and the other on.

Should be able to just put your meter on coil + and see what happens when you turn the key to Start. If it stays at 12, your problem is somewhere else, if it goes to zero, look for that other wire.

Edited May 22, 2012 by Zed Head

[rocketdog]

I am returning the Mallory to Summit as apparently the module is defective. I talked with MSA tech and did a test on the module which concluded I got a POS. Too much hassle for the $$ spent and the OEM dizzy and ignition work fine. Thanks for all your input. Fortunately I can just replug the OEM wiring. Won't have the mechanical advance option and the vacuum advance is disconnected for Webers, but I'm not racing the thing. Now I can play with tuning the Webers for the 4000 feet where I live.

[aceofspades]

sad i have a mallory and still trying to get the stock tach to work after works but is tiny I want the stock unit to work even if its crap! guessing i need a tech apdater