CAT 416B Issues

Have a CAT 416B (SN:8SG00445) that the block heater quit working on. It's under the manifold so I am guessing it has to come off to replace it? Or is there a way to get it out without removing the manifold? Also, the front lights don't work. It blows the fuse when the switch is flipped. I assume its a dead short to the chassis somewhere. Where does the wire run for the front lights? Up in the roof, or under the machine? TIA