I extended a wire for the ignition to install a kill switch. The switches at autozone were rated between like 5-50 amps, is there any preference here? The guy at the counter said 15-20 amps should do it, but what did he base that on? I was also going to put an inline fuse on the wire, he suggested a higher amp rating on the fuse then on the switch, while to me it would make more sense to have a fuse with a lower rating so it blows out before the switch gets overloaded? Also, once the car is running, will the power wire for the ignition still be in use, I mean the engine is getting it's power from the big wire by then, right? I just don't want to have the car die on the freeway, because I put a too weak switch/fuse in. If it would even work like that? Maybe once it's craning, the wire is irrelevant?
A little 5 amp one will be plenty. This assumes your splicing across the coil power wire to remove the wire, not ground out the coil. Very little load there. An inline fuse wouldn't hurt matters either. If you have an amp meter on your volt meter you could check the amp draw then typically upsize 10-20% for fuse. Now, if running an msd box or something simmilar and your tying into the power feed to the msd. go with the larger switch and I'd want to verify the amperage of that for fuse selection. EDIT: The guy at the auto parts store is a moron. You use fuses smaller than the switch PERIOD. With his mindset the switch would be the failure point; not the fuse. depending on you you do it either you'll need to but the switch in before both wires (12v (cranking) and the resistor wire (running)) you could do that with a double pole switch. and splice in anywhere and bring 4 wires back to the switch. OR you could splice in a new wire in front where the resistor wire and the 12v wire connect near the coil. then run that back near the switch. I hope this isn't too confusing. Nate
