FJ40 (May 1972) electrical issues (1 Viewer)

[landcruiserbob]

Hi everyone, I've had my '72 FJ40 since 1995 and pretty much all I have ever need to do on it is rebuild the carb a couple times. It's a tank. About two years ago the ignition key needed a little jiggle here and there to get it started. A few months ago it quit starting. I pulled the wiring harness behind the ignition key and it was melted and kind of burnt up. So I made new connections (IE homemade wiring harness) to the ignition key. Unfortunately, it didn't work and I later found that what actually fixed the issues was running a jumper wire from the ignition key to the coil. So I added in a "permanent" jump wire and now it starts and runs just fine.

However, I did some damage in the process... Now the following items are dead: fuel gauge, oil gauge, temp gauge and turn signals. The following are still working just fine Hazard lights, headlights, brake lights, wipers, interior light. I have continuity across all fuses. I think my grounds are ok- but that is just based on a jiggle test- so maybe I just have not found the right spot. I can't find where the short may be. How would you troubleshoot this further? I have a generic Fj40/55 wiring diagram that may not be an exact match to my month and year.

 

[badsamaritan]

Check the heater fuse, your gauges should be on that circuit which is fed by the ignition switch. then check for a blue red wire that comes out of the fuse block and goes to the gauge cluster barrel connector

 

[GatorPlater]

To me that sounds like you popped the fusable link. it is the hot side to the gauge cluster from the battery. You bypassed the link with your constant hot wire. Replace the link, then pull your ignition switch, clean and check for continuity.
That is what I would check first if it was me...
And it was me months ago, because that is what the PO did to get my 73 to crank and run.

Unless a 72 doesn't have a FL, which I haven't looked at that Diagram.

 

[landcruiserbob]

To me that sounds like you popped the fusable link. it is the hot side to the gauge cluster from the battery. You bypassed the link with your constant hot wire. Replace the link, then pull your ignition switch, clean and check for continuity.
That is what I would check first if it was me...
And it was me months ago, because that is what the PO did to get my 73 to crank and run.

Unless a 72 doesn't have a FL, which I haven't looked at that Diagram.

Thanks SlapSmak, I finally figured it out... All my fault... The Early '72's don't have fusible links. When I was running the bypass wire I abandoned the original (black w/ yellow) wire near the fuse panel. I ended up soldering the abandoned black w/ yellow wire to my bypass wire and now all systems are a go! Thanks for your help and suggestions.

 

[GatorPlater]

Good deal, glad you figured it out!