My pleasure. Glad I could help. I think a 15amp fuse should be enough. It really depends on how big the lights you're planning to use are, and by big I don't mean in size. I mean how much power the lights will use in watts. Watts=volts x amps. Lights' power consumption (watts)=your truck's 12Volts X Amps. Let's use a 200 watt light setup as an example. Divide the 200amps by your 12volts and you get around 17 amps. That means that your 200 watt lights will use 17 amps to work. You would want to use a fuse a bit bigger than that to allow for additional power loss in the wires, etc and so the fuse doesn't blow under normal use. So if you use a 20 or 25 amp fuse, it should be correct. You can use any values in that simple equation to plug in numbers from whatever lights you buy. As far as the trucks catching on fire, it may be poor wiring. I think cheap Chinese lights are more likely to not work than they are to catch on fire, but who knows. Maybe it's a bit of both.