which wiring harness do i need in order to install an aftermarket deck, i have a 1988 lincoln town car signature series, the wiring harness i purchased has two very long rectangular slots while i need one with a somewhat small and square slot and one long rectangular one, thanks

I also posted at LoL but, you need a ford premium sound harness with bypass. Metra number 70-5514, it has a long grey plug, a smal black square plug and two plugs with wire in between. Any stereo shop should have one.