• Fusible Links

    The FL 1.25B fusible link is a common problem area on these vans. To start with it's in an odd place. It's tucked up in the body just in front of the battery box. To get to it you have to lay on the ground with a flashlight, reach up to lift, then yank down off it's holding post. Another odd thing (considering this location) is it's not in a waterproof box. It is protected, well, sort of, but certainly not waterproof.

    Here is what it looks like while on it's mounting post.


    Here are some pix of what it looks like after being pulled down.




    Considering it's over 20 years old, the one in the pictures above is in remarkably good shape. This is a west coast van though with fairly low miles (about 100k) so it's had an easy life. The protective box on this one was wrapped with electrical tape and it looks like somebody put some sort of white grease on the conductors too.

    The "B" in the 1.25B relates to the diameter of the fuse wire. The bigger the wire, the more current it can handle before it blows. I don't have a conversion chart handy, but I'm estimating that 1.25B is equivalent to about 80A. You'd think by the mid 80's Toyota would have been labeling everything in amps &/or using conventional breakers / fuses. One would also think they would know better than to put a non-waterproof electrical connection (not to mention one of the most important ones) underneath a vehicle.......and oh yes, right behind a tire. Go figure .

    Here is a replacement fusible link wire. It is still available through Toyota for about $15. It's Toyota part #90982-08276



    Here is the next most problematic fusible link. The FL 0.5G fusible link is the yellow connector going to the positive battery post inside your battery box. It is rated at 0.5G (based on wire gauge, I'm guessing about 20A). This protects the alternator sense circuit that links the battery positive to the "S" terminal of the IC regulator. If this link is bad or disconnected, the end result is solid "Christmas lights" on your instrument panel and a "full field" condition in your alternator. Full field is when the regulator tells the alternator to go to maximum output all the time and can be dangerous. A short trip probably wouldn't cause any problems, but long term use could cause multiple electrical problems (due to over voltage) and worse case scenario could end with a thermal runaway condition occurring with your battery. Thermal runaways are scary and dangerous. The result is usually a pile of molten lead, plastic and battery acid all over the place. Thermal runaways have also been known to start fires, so don't push your luck with a bad or failing FL 0.5G link. Here is a what a typical 20 something year old one looks like:


    Although slightly more protected than the main fusible link, this link is still in a harsh environment and after 20 years or so will probably need some attention. I haven't checked to see if these are still available through Toyota, but really didn't see the need for genuine Toyota here. If Toyota still has these, they will no doubt want more $$$ for them than what they are worth. I have found a good substitute for these through Summit Racing for $2.95. These PICO fuse holders are water tight and are rated at 30A. Since this is a "sense" circuit, there would normally not be any current here, so I am going to recommend using a 15A ATC fuse. Here are a couple of pictures:






    These next fusible links are actually in a pretty good spot so they don't need much attention. Still, it's good to know where they are and what they do so I'm going to include these in this post.

    These are located in the compartment behind the front passenger seat. To access, slide the seat all the way forward, peal the carpet back, remove the single screw that holds the access panel lid, and remove it. This fusible link box is right behind the power steering reservoir:





    The EFI fusible link is rated at 30A and supplies power to the ECU and all the fuel injection related circuits. The AM2 fusible link is also rated at 30A and supplies power to the ignition related components such as the igniter, distributor, coil, and so on. The headlight fusible link is rated at 40A and you guessed it, it supplies power to the headlight circuit. The AM1 fusible link is rated at 60A and supplies power to all your accessories that come on when the ignition switch is in the "on" position. It is also the source of power for the starter solenoid circuit (trigger wire) when the key is turned to the "start" position.

    Last but certainly not least is the FL 2.0L fusible link. This one could be considered the most important because it supplies power to ALL the other fusible links (except the yellow FL 0.5G) This one is usually not mentioned due to confusion about it's location and because it rarely fails. When it does fail, most mechanics will bypass it without even realizing it's there. This is because it looks like an ordinary wire coming off the positive battery post. The 1st 6" of that "wire" are actually the 2.0L fusible link. The other end of this fusible link hooks up to a white wire with a blue stripe and that's the same wire that feeds the Fusible link that everybody knows about (the FL 1.25B). Here is a picture of the FL 2.0L. It comes from the factory in a soft loose fitting gray plastic cover.


    Here's a picture taken from the wiring schematic that I marked up. Enjoy. Tim
    This article was originally published in forum thread: The fusible link thread started by timsrv View original post