Fog Light troubleshooting

I installed fog lights in my cherokee this weekend and they're hooked up like so:

I spliced the 12V switched input that runs to my stereo and ran it to a 4 position terminal block.  All 4 terminals are connected together with a bus.  I then ran the switched input wire for the lights to one of the terminals.  I have the same configuration for the constant 12V.  I put both of the terminal blocks in a small plastic project case from radio shack, and drilled small holes to route the wire through.

Here is my problem, when I tested the lights, they worked fine.  Then I had my stereo on and cut the lights on after the stereo was turned on, and the stereo went out, then came back in.  The ignition was off at the time, so maybe that has something to do with it, or maybe its the fact that I spliced into the radio's wires.

I plan on installing a relay soon for the switched 12V, will that help me out on this problem?  Also, should I cut the wires going to the stereo and run the stereo off of the relay too?  Because now I'm tapped into it's supply.  Thanks for any help

here is the terminal block

Your probably running too much current from one switched power wire. Use the relay to activate a switched power wire as opposed to using a switched power wire from the fuse box or ignition harness. This will lower the cuurent draw from the stereo . I would use my parking lights to activate the fog lights or use the daytime running lights to do this as well.