i was hooking up some electric stuff to my car a few days ago. i got everything wired up and went to test it out. i turn ignition to "on" and flip the the switch and my radio and interior lights start to flash on/off. i thought this was really strange since the stuff i was putting in had nothing to do with either of them. i spent a while trying to figure out what i did. i had used the same ground that my non-stock fog lights use (crossmember under the radiator). i took the ground off and found a different spot for it. now everything works fine. can anyone explain this to me?

You say it works after you changed the ground? if thats the case the stuff was prolly just grounding out funny, or the combination of all the stuff probably wasnt lettin it ground enough~

Were the interior lights flashing on beat to the music? If so, I imagine all the power wasn't being grounded efficiently, causing interference in other electrical stuff.

If they were flashing at random, I guess my conclusion would be the same.