If your bird came with JBL system, you will have to rewire all 4 speakers direct to your Sony. I found out the hard way when I installed a Blaupunkt in my T-bird Factory speaker are routed thru the JBL amp. The Ford JBL systems were great when they worked, but a real pain when they quit. It took me the better part of an 8 hour day to accomplice this. Remove the door and rear side panels was not fun, but the results are worth it because my 28 year old JBL speakers still sound great!