2F swap ignition help

[oestlarsen]

I put a 1978 2F in my 1970 40.
A few facts:
Stock 70 harness:
- BY wire free ( assume goes to + on coil)
- BW wire on starter solenoid
- thicker W on starter
- thinner W on solenoid unused

Motor cranks


I am having problems figuring out how to hook the stock 70 harness up to 78 ignitor and dizzy.

1. So far only thing I can figure out is hooking free BY to + side of coil
2. Assume red and white wires from ignitor goes to dizzy (have to modify wires)
3. What other connections? All the wires from ignitor are already hooked up to coil.
4. Do I need a BW from solenoid to + side of coil too?

Is this a setup worth hooking up, or should I do something else? Need simple and as stock as possible.

Thank you!

 

[Pin_Head]

If you have a B/Y wire from the solenoid, it goes to the + side of the coil. The larger B/Y wire goes to the side of the ballast resistor that the ignitor connects to which is the opposite side than the one connected to the + side of the coil. You connect the distributor to the ignitor and it should run.

If you don't have the solenoid wire, then just connect the larger B/Y wire to the ballast resistor opposite from where it connects to the + side of the coil.

 

[oestlarsen]

Sir Pin_Head!
Like this?

 

[Pin_Head]

Maybe, but I can't really tell the necessary details from your diagram. The main power to the ignitor/distributor is a larger black wire with yellow stripe that comes out of the wiring harness. The colors may be faded, so peel back the harness wrap for a better look. It is hot in the Ign or run position of the ignition switch. This connects to one end of the ballast distributor along with the power for the ignitor. The other end of the ballast connects to the + side of the coil.

Most cruisers of that vintage also have a "ballast bypass wire" that in BY that runs from a connector at the starter solenoid to the + side of the coil. It is only hot during engine cranking.

 

[oestlarsen]

I checked the 1970 diagram again:

1. BW large wire goes to solenoid
2. BY wire small goes to + on coil


Does this mean i should run the small BY to ballast since BW must be hot on cranking only?

 

[Pin_Head]

The BW wire that attaches to a spade lug of the solenoid is the start wire from the ignition switch. It has nothing to do with your distributor.

The small BY wire that connects to a wire coming off the solenoid is the resistor bypass wire. You can skip this wire or connect it to the + side of the coil.

There should be a larger BY wire from the engine harness that is hot with the key on that used to connect to your coil. If you have the other end of the 78 green plug, you could connect it to the 78 ignitor. You could also use crimp on connectors to plug this wire into the connector with two wires that does not go the the distributor. Alternatively, you could connect it to the ballast resistor where the ignitor also connects which is opposite from the + side of the coil.

 

[oestlarsen]

Ok...I don't have a larger BY wire in my 1970 harness, so the time has come to deploy based on what I know and your excellent guidance. I will report back shortly with real data

 

[oestlarsen]

Ok...hooked up with making a bypass wire to + side of coil. bY to ballast.


Here is what i found;

1. No spark at plugs
2. Hooked up plug to coil, got 1 nice spark (blue)
3. There is power with IGN to ballast (checked with test light)
4. There is power to + when cranking per design
5. Checked coil resistance per fsm-passed
6. Here is odd thing....ballast gets VERY hot with key in IGN setting...

 

[FJ40Jim]

That's not gonna work. The ignitor/coil package is a 1977 for use with points.
The distributor is a 1978 w/ electronic pickup.
They don't speak the same language.

Keep the solid state dissy and get an ignitor/coil from any 78-87 2F.

 

[oestlarsen]

Well I'll be...
Without you guys, I would have been messing with this for months.
Thank you! Off to find a new setup...

 

[oestlarsen]

Update:
Sourced an FJ60 ignitor/coil setup for the 78 dizzy as instructed.

Wired as follows:
- tan wire to ign power (BY)
- white and red wires to dizzy

That's it...

Fired up right away!

BUT....she ran for about 3 seconds (sounded great), then blew a fuse :-(

The fuse is the lowest on panel. 2 wires go out (BY goes in)
- GO (appears to go to blinker lights)
- RW (per diagram goes to regulator)

Not sure if related, but my hazards have been funky and I was able to blow the same fuse, fiddling with the hazard switch and blinker. Will start there...

Next will be alternator circuit.

 

[hiboy]

I know this is an old thread, but , did you ever figure it out? I have a similar situation: 74 harness, large cap dizzy and ignitor -resistor/ballast system..have spent countless hours trying to figure out the wiring. Any ideas appreciated: igniter has black-yellow-brown-red -white wires. red-white go to dizzy on a connector, got that much figured out....the rest is GREEK to me...
thanks for your time.

 

[Pin_Head]

It isn't that hard if you didn't disconnect any of the ignitor wires at the resistor or coil. If it is still wired together as an ignitor/coil/resistor assembly look at the two terminals of the resistor: One is hooked to the + side of the coil and the other side is hooked to some wires from the ignitor. Connect your hot wire from the ignition switch to the resistor terminal that is connected to the wires from the ignitor. Make sure the ignitor is grounded. Connect the plug from the ignitor to the distributor and it should run.

You can skip the ballast bypass wire if you want, but if you have it and you want to use it, it connects to the + side of the coil.

If you have the ignitor wires disconnected from the ballast and coil, then you need to figure out which wires go where because I forgot and it isn't listed in the wiring diagram.

 

[FJ40Jim]

81-87 ignitor has

• wire that goes from power plug to coil + ring terminal, then supplies +12V into ignitor.
• wire from tach plug into ignitor. ignore for non-smog applications.
• wire w/ ring terminal to coil - terminal
• 2 wires that connect to distributor pickup w/ 2 pole plug.

Dunno colors, but the wires are all physically different so it's easy to connect correctly.