I have a 04 fire with the 8 speaker Monsoon and I wanna replace the deck with a aftermarket one will Metra wiring harness Part number 70-2003 work and still allow my factory amp to turn on and work also with my stock speakers im just replacing the deck not speakers, so my question is is my stock amp still going to work with this harness?
Yes, it should still work. You're going to have to run accessory power straight to the deck though since your car doesn't have accessory power coming directly off of the factory harness...
And to make sure your factory amp still works, just hook up the blue amp turn on wire...
that blue amp turn on wire, is it attatched to the cars harness? so i would have to cut it off of there in order to hook it up to my aftermarket deck? or does that metra harness have a blue remote wire to hook it up to?
The metra harness has it built in, so you don't have to cut any of your factory wire. It should be the blue/white on the metra harness. Just pair that up with the amp turn on wire coming off the back of your deck...