a while back while i had the intake horn off for some reason, well, after putting it all back together, i forgot to reconnect the two wires that go to the grid heater. they were touching other metal parts and when i started the truck they arced. there were some scortch marks on the injector lines and part of the battery cable blew out. Now i've noticed that the two nuts on top of the grid heater are rusted. This has been about a year ago, i reconnected the wires and had no other issues. Now, my batteries are bad, but i suspect that it is not related. they are the oem batteries from '02. I do however have quite a bit of corrosion on the passenger side battery. My questions are: do I need to replace the grid heater wires? Why are the nuts rusting? Do i need to replace the battery cables? I'm just wondering if what happened has led to some electrical issues. Thanks for the help.