Solara lights on without key in ignition

Someone help me please, this problem is driving me crazy and I can't seem to find someone to fix it - and I don't want to have to go to the dealer.
I have a 99 Toyota Solara with an aftermarket keyless entry remote starter on it - and we've already replaced the brain on that system and it didn't fix it.
During the day its fine but after it gets dark and you turn the car off and take the key out the dash lights headlights and taillights are still on and never go off and the oil light stays on on the dash and the little seatbelt flashing light stays on on the dash as well. I eventually have to pop the hood and unhook the battery to get them off.
Please help I have no clue what it could be.
Thanks!