How do you hook up the front two speakers on a 1995 Jeep grand cherokee?

I installed a after market radio in my 1995 Jeep grand cherokee, and it is working good. All four of the door speakers work. But I cnt get the front two speakers to work that are on the dash. How do it do this? I believe there is a factory amp. I do not have the factory wire connections on there becuase it was cut off when somebody stole my first after market cd player. Thanks