98 GS300 electrical problem

[Esperar13]

I have a 98 GS300 that I recently acquired with an electrical problem. It had about 6 to 8 blown fuses in the panel under the dash. Also, the previous owner hooked jumper cables up backwards and melted a big fuse under the hood (I think it was a 120A fuse for the alternator) it has a new fuse pushed down on top of the old one. I'm guessing I will probably have to replace the whole fuse panel under the hood. Anyhow, when I replaced the blown fuses under the hood (for wipers, ignition, radio, and I can't remember which others), the car started and ran, but the wipers won't turn off unless I disconnect the switch. The wipers are on the biggest fuse, and I'm thinking that maybe there is a short between the wiper circuit and the others with blown fuses, and since the the wipers have a much higher amp draw it is causing the smaller fuses to blow and giving power to the wiper circuit where it shouldn't be. I looked under the dash and hood and I can't see anywhere where the wiring harness is damaged. The plastic loom is intact throughout. I think my next step will be to pull the loom off and see if the wires have gotten hot and melted the insulation off. Has anyone seen this problem before? This is my first Lexus. Thanks in advance!