[mc88]

Hopefully someone will correct me if I'm wrong, but a relay is pretty much just a beefed up switch. If you run all those amps through some of the little switches (like the horn or lights) it's too much for the switch to handle and can ruin the switch.

And on my last bike I had a fuse box with one relay that I wired to the running lights which only came on when the bike was running. So then if I shut off my bike and forgot to shut off something else, I wouldn't come back to a dead bike. I had a real bad habit of leaving my EMT lights going after I shut off the bike and jumped off to run into the ambulance garage.

And I'm pretty sure if you use a realy for the fuse box, you won't need a separate relay for the lightbar, but better take advice from and expert, which isn't me. haha