You can get an expensive adapter (try crutchfield) to run an aftermarket head with the bose amp/speaker combination. Since you have run the head unit without an adapter, you may have damaged 1 or more of the amps. You should have them checked before getting the adapter. The second option is to delete the amps and replace the speakers. I chose this option. I also ran new speaker wire at the same time. The new wire is a larger guage and will carry a load better. I have heard that you can use the signal leads from the factory harness without the amps, but have not tried it. When I replaced my speakers, I enlarged the cutouts in the enclosures to fit 6x9 in the front and 5x8 in the rear. I also insulated the speaker boxes. This made a ton of difference in the sound quality and volume levels. Hope this helps.