'74 FJ40 Ignitor Question (1 Viewer)

[OldRocDoc]

I am restoring a June 1974 FJ40. At some point in its history, the igniter and electrical connector to the wiring harness were removed. I purchased a used igniter assembly (89620-22011) that I believe was used on CA-spec Cruisers from 9/73 to 6/74 (Thank you Pardion).

The wiring colors inboard of the connector to the Nippon Denso igniter do not match those of the Toyota wiring harness. According to all of the wiring diagrams I have seen, the harness end of the connector has the following:

• BY -- switched 12v
• B -- to negative terminal on coil
• R -- to distributor
• WB-- ground

The wiring from the connector to the igniter assembly (see pic below) has the following:

• B
• R
• Y
• W

Clearly, Toyota and Nippon Denso are using different color schemes. I am assuming that B and R are the same on both sides of the connector, that the igniter Y should connect to the harness BY and that the ignitor W is the ground.

Could the electrical gurus either confirm my assumption or tell me to grab the fire extinguisher

 

[thebigredrocker]

Found a similar thread. Not sure it has your answer. wiring nightmare

Maybe @Pin_Head will know what to hook up.

 

[Pin_Head]

The wiring from the igniter to its connector is a different color code than the chassis wiring and it is not shown on the schematic. Hopefully, you still have the other side of the connector to just plug it in. Otherwise you will need to find someone that that has the original connector intact to decode the wiring or you will need to “read” the schematic of the printed circuit of the igniter to see what wire goes where.

My recollection from my ‘76 was that red went to the points and black went to the coil -, but I could be wrong or the wiring different.

 

[OldRocDoc]

Sadly, the harness side of the connector is MIA. I was hoping someone on the forum might know or be able to check the connections if they have a similar igniter. My ability to "read" the schematic is unfortunately limited.

 

[Pin_Head]

The circuit is pretty simple. Typically two large power transistors in series. I don't know what the two high watt resistors are for, but maybe it is power for the transistors. Take the cover off and take a picture of both sides of the PC board at the highest resolution possible and post up the images. I have a guy that used to work for me that can "see" the schematic and how it works. He is an EE that used to work for HP and Rockwell that is retired. Maybe I can get him to take a look. He has repaired a number of PC boards for me.

 

[OldRocDoc]

Thank You, Pin Head.
Here are some images of the circuit board

 

[Coolerman]

Interesting. The documentation I have on 1974's does not mention that California spec FJ40's had igniters. My docs show the igniters did not start until 1975. Guess I'm about to learn something!
If you have an Ohm meter, see which lead is attached to the igniter case. That one would be the ground lead.

 

[JohnnyC]

@Coolerman

I did notice on this great site that has schematics (lol) there is a 74’ fj55 diagram with a igniter

Supposedly my 74’ 40 was a ca truck that came east at some point and I do not have one... mine is somewhat butcherd thru the years however

 

[Coolerman]

Well if one could infer that the FJ55 igniter is wired the same then here is how to connect it:
Igniter Yellow to Harness BY
Igniter Black to Harness Black Coil -
Igniter Red to Harness Red Distributor
Igniter White to Harness White/Black

This would also sort of follow Toyota's wiring color scheme for regulator wiring where the stripe color of the wire on the harness side is the solid color on the device side.

 

[Coolerman]

I also just went through my admittedly limited collection of 1974 FJ40 pics. I could not find a single one showing an igniter. All I see is a coil and ballast resistor and a wire from the coil to the dizzy.

 

[Coolerman]

Toyota Parts Deal says that part number 89620-22011 fits 1973 to 1975 FJ40 and FJ55 Land Cruisers. If their site is correct, I guess some 1974 FJ40's did come with igniters. FYI it also states that Part # 89620-22020 replaces that part number.

 

[Pin_Head]

@OldRocDoc I know enough about DC circuits to tell that the red wire is from the collector (case) of the big power transistor, so it attaches to the - side of the coil. That means that the yellow wire goes to the points because it goes to the base of the smaller power transistor that drives the big boy. That means that the black and white are power to the circuit, which makes sense because they are connected to the big power resistors that limit the current. Just guessing from Toyota convention, the black is + and the white is -. If the white is connected to the case like @Coolerman suggests, then that verifies that it is the ground.

I have included a link to a generic transistor igniter circuit. The right half is relevant to this discussion and the two power transistors in cascade are at the bottom of the diagram.

https://www.electroschematics.com/555-ignition-coil-driver/

I would clean off the circuit board with a Q tip and some windex or isopropyl alcohol. It looks like there is some corrosion.

 

[OldRocDoc]

Thank you Coolerman and Pin Head for your input -- it is greatly appreciated.

I am very confused

After stripping off tape and looking more closely at this harness, I do not see any evidence that a 4-pin connector that might link to the 89620-22011 Igniter has been removed. This leads me to think that this FJ40 indeed never had an igniter.

On the other hand, I see this thread from Trollhole on a '74 CA Spec dizzy replacement that clearly shows the 89620-22011 Igniter:

Electronic Distributor Trollhole in a 1974 FJ40

Is there a way to tell from the distributer whether or not it was using an igniter, or from the VIN if it was indeed a CA vehicle?

Input from Trollhole would be greatly appreciated in clarifying the timing and usage of this igniter on USA FJ40s

 

[Pin_Head]

If it is a CA spec smog truck, then it should say CA spec on the tag in the engine compartment. The plug may have been part of a separate harness and not connect to the main harness. The wires don’t have to run far. It would get power from the key side of the ballast resistor, connect to the points and the - side of the coil and a ground somewhere. The igniter should work with any points style distributor.

Are you doing this restoration as penance for the blasphemy you have done to other Landcruisers over the years? Lord knows I have cut up my share.

 

[OldRocDoc]

Are you doing this restoration as penance for the blasphemy you have done to other Landcruisers over the years? Lord knows I have cut up my share.

I am hoping the Cruiser Gods will view it that way and have mercy on my soul

In fact, I inherited this and another mostly disassembled FJ40 from my brother. He tore them both completely apart with the idea of making one complete restoration. He became ill partway through the project, and I ended up with all of the parts -- many of which managed to become lost. Because it is largely rust-free, I decided to try to complete the full restoration of the '74. I have been trading for, and buying parts over the past two years in the hope of bringing it back to OEM quality. At some point it was re-painted and the engine bay tag removed -- hence my uncertainty whether or not is was CA spec .

I hope to have the restoration complete within the next year. Last year I worked on the chassis and have refreshed the entire drivetrain. I just finished the body work and painting of the tub, so it is starting to come back together.

Thank you for the help Pin Head!

 

[Pin_Head]

If your ‘74 carb is original and has an EGR inlet tube, then it is a CA model. Pardion is the go-to guy for rare CA spec parts. I bet he did his share of blasphemy back in the day.

 

[Tractor Dave]

Pinhead,Coolerman,OldRocDoc,you all just solved a mystery for me and my basket case 9/1973 thank you greatly !!!

 

[Tractor Dave]

This is harness connector front right side engine bay