Originally I replaced the tiu with an hei module and a stock coil. I was getting weak spark, so I decided to upgrade to the flame thrower and msd blaster. I think I messed up the wiring or I don’t have something connected right.

I don’t remember where I got the 12v from and I can’t find it with my multimeter. I’ve looked at diagrams I’ve been able to find but the ones I found were for a 77 with a different different setup and one for the 240 with a different ballast and wire colors.

can someone help me out pretty please and thank you!

The long white wire at the top is not connected and I tried hooking that up to the green wire at the ballast. I think I’m missing something on th positive side of the coil.

I am assuming you are using the 4 pin HEI module. Also, I believe that is a blue wire on the ballast resistor.

The W terminal gets the red wire off the distributor pickup. The G terminal gets the green wire off the distributor pickup.

The black/blue (Ignition power for cranking) wire and black/white (Ignition wire for running) wire will get tied together and go to coil positive and to the B terminal on the HEI.

The C terminal goes to coil negative, and you keep the blue wire on coil negative for your tach signal.

References:

I have no blue wire, thats whats confusing me. If I hook it up to the green wire, i get nothing. I think originally with the old coil thats where the green wire was hooked up on the ballast. Do I need to do anything with the other wires on the ballast? Is the green wire actually a blue wire thats faded?

Don't know if this will help. L = bLue, BL = Black w/blue stripe, RW = Red w/white stripe, WB = White with black stripe. Notice that the blue wire is just passed through the ballast resistor directly to coil negative, using the stud as a terminal post. They could have just run it directly to coil negative.

After blue leaves the diagram it heads off to the ignition module by the fuse box, and the tachometer. With the HEI conversion you wouldn't need the blue wire back to the cabin (module and tach) to make the engine run. But it is needed for the tachometer to work.

You don't really need the ballast resistor anymore. You can find your power wires by turning the key on and measuring voltage, and by turnng the key to Start and measuring voltage. Those two should go to coil positive. The wirng diagrams can be confusing because sometimes they show connections that are just there for convenience. It helps to think about what needs power, and when it is supplied.

I think though that Nissan also used one of the terminals as a connection post for AC clutch power. One of those "why is this wire here?" things.

Might help to expand your picture and show what those green and white wires are connected to. What you're looking for might be buried in the harness. Those wires are not factree.

It is indeed a blue wire. Clean it.

This is from the factory wiring diagram: (Note - I cleaned up the text for the wire colors to make them legible.)

There are 5 wires going to the ballast resistor in stock form. Two are blue wires. One blue goes to coil negative, while the other blue goes to the TIU and resistor for the tachometer. The white/black wire goes to coil positive. The black/blue goes back to the ignition key where it is powered when the key is in Start. The black/white wire is the 12VDC+ source when the key is in On.

Thanks so much everyone! I’ll give it a go here in the next couple days.

22 hours ago, nowak1981 said:

I have no blue wire, thats whats confusing me. If I hook it up to the green wire, i get nothing. I think originally with the old coil thats where the green wire was hooked up on the ballast. Do I need to do anything with the other wires on the ballast? Is the green wire actually a blue wire thats faded?

I’m not sure I fully understand your comment about the blue wire—there are two visible on the ballast resistor in your photo.

1. The light blue wire to the coil negative (-)

2. The light blue wire from the TIU, located in the passenger-side kick panel in the cabin

3. The black/white stripe wire from the ignition switch (ON position) goes to the ballast resistor (0,9 ohm)

4. The white/black stripe wire to the coil positive (+), supplying reduced voltage via the ballast resistor

Additionally:

5. The black wire from the ignition switch (START position) acts as a bypass for part of the ballast resistor, reducing it to 0,4 ohm, increasing the voltage to the coil during cranking. This compensates for the voltage drop caused by the high current draw of the starter motor.

I made a strip to bridge the three points 3, 4 and 5 on my ballast resistor for my 280Z some years back. That way the coil will get full battery voltage all the time. Here are some photos. If you want more detail, let me know?