Why did I blow a fuse when putting new taillights on my Scion Xb?

Question

Is it because I did not unplug the battery, or is it because the new taillights have an led component, I am debating if I should try to put them on again, the dealer said the will not fix the fuse next time and it will cost $150, advice is appreciated.

Answer 1

LED lights will probably draw less current than the old lights and wouldn't blow the fuse. You either wired it up wrong or had the light switch on and shorted out a wire when you were wiring it. There's no need to disconnect the battery as long as you don't have the taillights turned on.
Why would it cost $150 to replace a fuse? they cost about 10 cents apiece and take two minutes to replace.