Either your cables are hooked up wrong or you have one heck of a short circuit. Typically your positive battery cable will connect to the starter solenoid and the negative to chassis ground.

Can you give more info? When did the problem start? Did you do any work to the car recently?

The large cable that goes into the fuse panel connects to the POSITIVE battery terminal.  The large cable that is connected to the vehicle frame or sheet metal goes to the NEGATIVE battery terminal.

Have you tried going to the parts department at a Toyota dealership and asking for help? Usually they can pull up diagrams of just about everything. If that fails, can you find a T100 for sale that you can go look at?

Why is my negative battery post sparking smoking and melting when I try to connected it

Does rhe black battery cable that goes under and into fuse box hook to the positive or negative battery post on my toyota t100 4x4 ex cab 215665mi automatic

Help this internet is driving me nuts I've spent about an hour or so trying to ask a question 

Thank you for last input that I recieved , however on my 1997 toyota t-100 4x4 ex-cab automatic 5vzfe something doesn't seem right when I go to hook it up the way you suggested my cables do not reach my battery post. The police post is toward the front of the vehicle on the left side . When I took it , he battery post all apart to clean and the went to hook cables back up that is when I encountered the neg post melting and the cable slipped on accidentally for about 10 or more seconds .bacically I've got a positive red cable and a small black cable with grey stripe on the left side with the red cable going under truck and the black and grey cable connecting to the engine block. The other cable on right side goes under the fuse box and hooks near the alternator fuse and another small short black cable goes from side of truck to neg post.prior to this problem I just encountered with truck not wanting to turn over my door module on drivers side fried I put different one in not from same yr truck and was working fine but for longest time my truck did not want to start with a warm engine it would turn over though. I do not know how if I may have fried both modules and took both of them out and they look fine with no burn marks I did spray them a long tome ago with BP blaster and some wd40. But just recently spayed ccr electrical cleaner on them and let them set. It is sitting at a mechanics drive right now and I don't know when they are going to get to it . I would like to still try to see if I get the battery cables hooked up correctly if I could get back to square one of my truck just not wanting to turn over