Today I installed a Wolo 843 12V train horn. I decided to test the horn and see if it worked, and after I pressed the button it sounded for a quick second and stopped. I tested it with the car being off, not sure if that has anything to do with it. But when I go and try to start the car, it won't start at all. All of the regular interior lights come on, but when I turn for the ignition, everything goes off.

Anyone have a problem like this before or knows what to do? Thanks!

 

Of course you tried jumping the battery, right?

Check the battery connections for anything loose and all of the ignition fuses and breakers. There is a giant ANL fuse in the fuse box that I have heard of blowing with amp installs.