Wire ID (1 Viewer)

[777sam]

USA 1978 FJ40
Photo location: above passenger front wheel well.

Project: I’m in the process of installing a new distributor.

I have a stock Toyota electrical connector that appears to have two black wires with yellow tracer stripes. One is a heavier gauge wire than the other.

Which one is the ignition B+ ?

What is the other wire?

Which one do I run to the distributor?

I have another white wire above the wheel well that might be the dedicated ground? The wire is wrapped in the wire harness but I’m not sure it’s original? I can investigate with my multimeter.

Here are some photos:

Thanks!
Sam

 

[B y r o n]

Where is your igniter? Have you looked at a wiring diagram? You can find one here if not.

 

[pb4ugo]

So without looking at a wiring diagram, the white wire goes to the batt and needs to have a fusible link, similar looking to your 1st pic. The black/yellow stripe is the ING wire. Your missing the coil which might have a plug on it.

 

[777sam]

Where is your igniter? Have you looked at a wiring diagram? You can find one here if not.

I need to buy one. Any recommendations? Go with a 1978 or are there newer more reliable models?

So without looking at a wiring diagram, the white wire goes to the batt and needs to have a fusible link, similar looking to your 1st pic. The black/yellow stripe is the ING wire. You’re missing the coil which might have a plug on it.

Have a coil but which of the two wires do I use? They both appear to be black with a yellow tracer?

 

[777sam]

So without looking at a wiring diagram, the white wire goes to the batt and needs to have a fusible link, similar looking to your 1st pic. The black/yellow stripe is the ING wire. Your missing the coil which might have a plug on it.

 

[fjc-man]

Does your new distributor have points? Your original coil would have had a transistorized ignitor mounted on it.

 

[777sam]

I need to buy one. Any recommendations? Go with a 1978 or are there newer more reliable models?






View attachment 3488068

Have a coil but which of the two wires do I use? They both appear to be black with a yellow tracer?

Does your new distributor have points? Your original coil would have had a transistorized ignitor mounted on it.

Sounds like I need to buy an igniter and the wires might make more sense.

 

[fjc-man]

This is what it had originally. Does your distributor look like this inside? Or does it have points?

 

[Coolerman]

First the wire for the coil/igniter is the larger 14ga BY wire.

Second: Be careful if you plan to use the coil that you posted a pic of in post #5 with the ballast resistor installed.
Your 1978 has a "built in" ballast resistor wire inside the main cowl harness instead of having an external physical ballast resistor for the coil. This resistor wire is made by Yazaki, is colored PINK and has a resistance of 1.2 ohms just like a ballast resistor. This wire starts at the key switch as a BY wire, the pink resistor wire is spliced to it about 18 inches down inside the harness. The pink resistor wire then runs through the harness and at the firewall is again spliced to the larger BY wire that comes out in the 2 pin plug shown above.
If you use the coil pictured as is without removing that ballast resistor, you will in effect have TWO resistors in series and you will only have about 6 volts on the coil which is not enough to create a good spark.
So in summary, if you use THAT coil, remove the ballast resistor. If that is NOT the coil you plan to use then make sure whichever coil you use it is rated to use a ballast resistor.

 

[777sam]

First the wire for the coil/igniter is the larger 14ga BY wire.

Second: Be careful if you plan to use the coil that you posted a pic of in post #5 with the ballast resistor installed.
Your 1978 has a "built in" ballast resistor wire inside the main cowl harness instead of having an external physical ballast resistor for the coil. This resistor wire is made by Yazaki, is colored PINK and has a resistance of 1.2 ohms just like a ballast resistor. This wire starts at the key switch as a BY wire, the pink resistor wire is spliced to it about 18 inches down inside the harness. The pink resistor wire then runs through the harness and at the firewall is again spliced to the larger BY wire that comes out in the 2 pin plug shown above.
If you use the coil pictured as is without removing that ballast resistor, you will in effect have TWO resistors in series and you will only have about 6 volts on the coil which is not enough to create a good spark.
So in summary, if you use THAT coil, remove the ballast resistor. If that is NOT the coil you plan to use then make sure whichever coil you use it is rated to use a ballast resistor.

Without the ballast resisor, how many volts should i see at the coil?

I took some voltage readings:
Bat 12.5
Voltage from Ignition 10.0V
Down stream of ballast 5.0

Sounds like your right. Will 10.0 volts work at the coil if I remove the ballast?

Thanks,
Sam