Ignition Shorting Issues 6/72 FJ40 (3 Viewers)

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Good evening folks,

I have been having some issues with my 6/72 FJ40, and am a bit stumped as to where to go.

Around this time last year, I learned that my Fusible Link went bad after my FJ just stopped any electrical. My 40 has been running well until about a month ago, where all of a sudden, it wasn't turning over. That turned out to be a bad battery, but I also put in a new starter as my starter seemed to be making clicking noises but not turning the engine.

Fast forward to today, new starter, new battery, new day. Get those both installed, and he begins to turn again, and maybe 2 seconds in, dies. Turn the key again, nothing works. I figure that the Fusible Link went bad, but my wife was in the garage at the time and said she swore she saw a spark under the truck before it went bad.

I am scratching my head, as I am not experienced in Electrical Diagnosis. I recognize that a new fusible link is likely in order, but the fact that this happened twice in a relatively short period of time, I am not sure where to start. Does anyone have any tips?
 
Good evening folks,

I have been having some issues with my 6/72 FJ40, and am a bit stumped as to where to go.

Around this time last year, I learned that my Fusible Link went bad after my FJ just stopped any electrical. My 40 has been running well until about a month ago, where all of a sudden, it wasn't turning over. That turned out to be a bad battery, but I also put in a new starter as my starter seemed to be making clicking noises but not turning the engine.

Fast forward to today, new starter, new battery, new day. Get those both installed, and he begins to turn again, and maybe 2 seconds in, dies. Turn the key again, nothing works. I figure that the Fusible Link went bad, but my wife was in the garage at the time and said she swore she saw a spark under the truck before it went bad.

I am scratching my head, as I am not experienced in Electrical Diagnosis. I recognize that a new fusible link is likely in order, but the fact that this happened twice in a relatively short period of time, I am not sure where to start. Does anyone have any tips?
Post some pics of the starter wiring
 
Just because you bought and installed new parts doesn't mean they are good.
Load test the battery. I put 2/O battery wires on my rig recently - what a difference The red pos + goes right to the starter, other pos attach at the battery clamp. I ran the black -neg right to the block and used the old 2 gauge wire from the block to the frame. I think there is a copper flat strap from the frame to the chassis.

You can work on the starter - clean the computator, make sure the brushes are good. I took the solenoid apart and flat filled the big copper disks to clean off the damaged arc spots. I think the info is in the factory manual and the haynes book.

You can test the starter with a set of good jumper cables, I like to do it on the ground. Clip one cable to the other so they can't touch then attach the other end of the jumper cables to the battery. Now connect the loose neg black to the mounting flange on the starter. Step on the starter to hold it in place - press the + red to the copper stud on the starter solenoid hard. Sparks will fly so don't do it on/next to combustible stuff. A good starter will lurch and roar to life plus the (bendix?) gear will leap forward towards the nose cone as to engage the flywheel ring gear. When you remove the + lead from the solenoid the bendix should snap back to the home position.

I think the fusible link is directional - if you put it on backwards it will fry - that is/was the electrical protection for people that hook up jumper cables wrong.

Free download manuals Land Cruiser Factory Service Manuals (FSMs) - https://www.cruisercult.com/factory-service-manuals
 
There's an earth strap from the chassis to your bellhousing - check that's there and in good condition. On my 2fs its held to the engine by the bottom starter bolt. Crappy connection at an end will spark. Fusible links are just a length of skinny wire with a fireproof outer, I replaced mine with aftermarket ones, have a read in my long thread.
 
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When I have starter issues, checked the battery by load test it with the starter, check for loose connections, clean the terminals-both end with a wire brush, will somtimes oxidize. You also connect a volt meter to battery, applying a load should make the volatage come down a couple volts and climb back up to 12v after the load. I understand you already purchased a battery and starter but I'm suggesting this incase others have a similar issue.

To test the starter, I usually turn the key to the on position on the ignition sw. and I like using a remote starter. Should turn be able to start engine. If are uncomfortable testing it, try starting it with the key instead. You can also remove the starter and take it the auto part store, same for the battery And have them load test it.
If it clicks but does not start watch the volt meter as you put the load. I will use the booster cables and connect the ground to starter chassis and the other end to the battery. Try to start it. No joy, I try the same thing with positive side. If starts with booster cable as jumpers, you may have oxidized battery cable ends. If don't have a ground cable from the frame to the starter, install one, it does help. You usually see them on fj60s newer fj40s. Anyhow, cleaned the terminal ends with a wire brush. Or replace them like mentioned above. I usually make my own, I crimp them and put heat shrink over the terminal and cable. It's pretty easy to make them. I used a crimper from work but you call around and somebody should be able to crimp them or get one them fancy hydraulic crimpers from Harbor Frieght. I hope this helps, good luck
 

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