The other day I had to jump start my Maxima with a completely dead battery which I know is a no no. Well I managed to blow the 140amp fusible link. I've since tried to replace it with a couple 120amp fuses but they blow out seconds after hooking up the battery. The only place I can find the correct 140amp replacement is online but I would hate to spend the 20 some dollars on it only to have it blow as well. I'm sure I have a short to ground somewhere but none of the other fuses in the box are blowing, which lead me to believe I don't have a short on any of the other lines coming out off the box. So should I assume it's on the main positive battery cable that runs right into the box and into the fuse? Could a bad negative battery cable cause this as well? Also, I'm wondering if I should test that the starter doesn't have a short to ground first and go from there? Any help regarding this is appreciated as my electrical diagnostic abilites are rather limited obviously lol.

 

Boss, if the circuit is rated for 140 amps, a 120 amp fusible link will fail every time as its not rated for that amount of current. Your approach is interesting as most will up size the fusible link thinking the engineers didn't know how to properly size the silly thing 20 some odd years ago when new. You have a short(s) in your system somewhere that you have to find and resolve. Otherwise your are just throwing $20 bills at your problem and raising your blood pressure. Get your battery charged or replaced first. Then with a wiring diagram, a simple multi-meter/VOM and your eyes start tracing down and visually inspecting wires. You could easily rule the starter in or out by taking it to an auto parts store to have it tested. Most stores will do the test for free and its a 20 minute job to remove your starter. Plus by removing your starter you would isolate the 12v+ cable so that continuity and a complete visual inspection can be made of it.

If you don't have a multi-meter, Harbor Freight gives them away for free with a nominal purchase. By the time you identify your problem your electrical trouble shooting skills will be greatly enhanced or your wallet will be lighter. Make a list and verify one thing at a time. Report back as you need to.

 

That fuse is not on the starter. Disconnect the wire to the alternator and see if the fuse still blows.

A bad negative cable will not cause the fuse to blow. If the insulation is cut and the cable is shorted to ground, well, that's what a negative cable does. If the cable is open, as in cut or something, then nothing will happen the same as if the battery was not in the car.