long and short of it all---i stumbled on a YT video where a shaaady mechanic tampered with a customers (fuses /fuse block)vehicle to make it run horrible.......sidenote........at this time i had just had my own vehicle worked on and noticed my truck wasn't shifting right....cowinky dink....oddly...so i checked my own fuse block and pulled the fuses that tell the trans-mission to shift...........wait for it....this is where my question comes in ......when i pulled the fuses i found what looked  like a yellowish coating on the prongs of all the mini fuses i pulled ........my question is this some type of coating =corrosion or did someone spray something on the fuse block to make it have  better electrical contact ----or to protect it from moisture? just asking because you have seen it all before....