Resistor wire failure....acting like a ballast resistor failure

[bmgraw]

Good morning. I have a Nov 1977 US spec FJ40 that's acting like a failed ballast resistor. It's a daily driver for me and needed some new coolant hoses, so after the project I cranked it to let it run and warm up. While idling it stalled and won't crank again. It starts and stays running if I keep the key in the start position. The second I let it turn back into the run position, it dies. I replaced the fuel filter and fuel pump and it's getting plenty of fuel to the carb. Having ruled out fuel issues, it's down to this, I think? Not as simple as replacing the ballast resistor though. Here's what I found:

A 1978 Toyota Land Cruiser (FJ40) uses a built-in pink Yazaki resistor wire (about 1.2 ohms) inside the main cowl harness instead of a physical, firewall-mounted external ballast resistor.

I've learned to fix mechanical things on cruisers over the years but to date haven't had an electrical issue on many cruisers.......so I don't know where to begin. Is there a way to bypass this resistor wire and install an external ballast resistor? Is there a fuse for this resistor wire I should replace first? Other solutions to get me up and running? I haven't found anything in ih8mud regarding this particular issue on a model with the Yazaki resistor wire. Any help with this would be greatly appreciated!

Ben in Boerne Texas (near San Antonio).

 

[ceylonfj40nut]

Pics of said Yazaki wire area. If you have good fuel coming in and fuel bowl level is to factory spec (assuming you have OEM carb) what controls your idle circuit is your fuel cut solenoid on the carb. Confirm that it is working properly and that it’s getting consistent 12v power at idle. Your key switch end of your harness maybe faulty as well.

 

[Engineer8000]

Possible ignition switch problem, not supplying 12V to the coil resistor wire after starter drops out? Bad engine fuse? Check to see if you have 12v on the load side of the engine fuse and at the distributor with ignition on. Look for bad connections or PO hackery around the pink Yazaki resistor wire. IIRC it is buried in the harness.

 

[bmgraw]

I pulled the engine fuse, tested it and it’s fine. I don’t show any voltage on the load side of the engine fuse…..if I’m checking it correctly. I compared it to the radio fuse and got 12 V but got zero on the engine fuse. Also got zero at the distributor with ignition on.

I’m having to Google how to use a multimeter so really I’m pretty green with anything electrical. Really appreciate any insights.

Thanks
Ben

 

[bmgraw]

Also reading nothing at the coil.

 

[Engineer8000]

Radio is fed from ACC contact in ignition switch. It sounds like the Ign contact is not working if you are measuring correctly. Or possibly a bad connection somewhere near there on the BY wire.

 

[Engineer8000]

You can probe the BY wire from the rear of the ignition switch connector under the dash. Check both sides of the connector with IGN on. Might have to remove the column clamshell.

 

[bmgraw]

Will you look at that!? Engineer8000 you called it! Now, how do I go by fixing this?

Grateful!
Ben

 

[bmgraw]

 

[Engineer8000]

It's pretty easy to swap out the ignition switch. Just pop off the clam shell and take out the screw, it will pull out of the bracket.

 

[Engineer8000]

I did not see your pic before responding. It looks like the solder broke free from the contact. You can remove the old solder and try to solder it back on. Be careful or the plastic will melt.

 

[Engineer8000]

Thinking about it, this might be a process failure when it was made. It could be the other solder connections may be ready to fail too. Do you see any cracking?

 

[bmgraw]

I don’t see any cracking on the others, but I also can’t tell if the terminal has broken off or if it’s the actual soldering. I don’t know what the terminal is supposed to look like.

 

[bmgraw]

New switch ordered! Many thanks for walking me through this.

Ben