FZJ80 Fusible link / alternator diagnosis help required (1 Viewer)

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Aug 9, 2008
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So my 1994 model 80 blew a radiator hose. I got a full set of new hoses and drive belts to install, but in the meantime I just replaced the burst top radiator hose.

I removed the bottom bash plate/guard in anticipation of replacing the lower hoses. I didn't get to finish the job and in the mean time I drove through a large volume of water. Engine stalled and it took me a while to restart the engine. Made the 1 hour drive home fine.

The next day all the dash lights came on when the engine was running, indicating a non-functioning alternator.

So I pulled the alternator and gave it a thorough clean out as per a great thread here:

Alternator clean and rebuild

I checked the alternator condition and the tests on the bridge rectifier diodes showed some had burnt out. So I replaced the entire rectifier/regulator/brushes with a new assembly.

The diode check method is shown in a video I posted in the above linked thread.

I just finished putting everything back together and as I installed the battery terminal I let out all the smoke - coming from the fusible link. This was with the key out of ignition switch and everything turned off. I don't know if the fusible link was partly burnt out already from the previous alternator issues.

I pulled the entire link out and the main green wire was melted all the way through, no conductance.

My question is, can I just temporary install a home made fusible link to test the system, or if I use a wire too large am I likely to burn everything out? Obviously the link is supposed to burn first rather than melt expensive components.

I don't want to go an buy the new link from Toyota just to burn it out straight away.

Or are there some checks I can do before I replace the link? I already checked and the alternator wire is correctly on the B+ post, and the 3 other alternator wires are plugged in properly. I have really messed with any other electrical connections.

I won't be able to get to Toyota spare parts until Monday, so have some time to test things.

Thanks for any advice.
 
Is it possible that you pinched a wire somewhere while installing the alternator? Did a wire somehow get grounded to the case of the alternator? Did you check the polarity when you installed the battery? I would start at ground zero of where you know you had a problem and work from that point. You could probably build some hillbilly fusible link but I wouldn't waste the time. You need to just grind out some basic continuity checks.
 
Thanks, I will get the multimeter out tomorrow and see what I can find. The rear housing on my alternator was a bit dented in places. You have me thinking that maybe the housing has shorted out on the components inside. Will check that too.
 
I pulled the entire link out and the main green wire was melted all the way through, no conductance.
To be clear, there is no "green" wire in the OEM fusible link set.
FL AM1 is BLACK = 80 amp
FL AM2 is PINK = 30 amp
FL MAIN is BLUE = 100 amp

THIS PICTURE SHAMELESSLY PILFERED FROM ABSOLUTE WITS END.
1627737390413.png
 
I'm in Australia and the FL MAIN is green. Not sure if this is a RHD thing, but that's what it is ;)
 
I'm in Australia and the FL MAIN is green. Not sure if this is a RHD thing, but that's what it is ;)

It's an 'Envy' thing.....of the U.S. marketed vehicles. ;)
 
Green would be 40 amps. I assume your 80 does not have a 1FZ engine.

So I tested the alternator and the B+ terminal had continuity with the body of the alternator. Removed it and fixed now.

Also my new fusible link came in today, compare the dirty (and partially burnt out) 27 year old link and the new one. I guess this explains why there was some discrepancy in the described colours. :) Note the main wire was even dirtier and darker before I gave it a clean with some degreaser.

210805 fusible link.jpg
 
So I tested the alternator and the B+ terminal had continuity with the body of the alternator. Removed it and fixed now.

Also my new fusible link came in today, compare the dirty (and partially burnt out) 27 year old link and the new one. I guess this explains why there was some discrepancy in the described colours. :) Note the main wire was even dirtier and darker before I gave it a clean with some degreaser.

View attachment 2750691
I think you got your moneys worth out of that link. Good job on finding the problem.
 

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