Cadillac Repair: trouble with cranking car, radio wiring harness, inline fuse

Question
QUESTION: I've been told by a few people that had the same problem as i that there was an inline fuse in the vehicles wiring system somewhere that if blown would stop the car from cranking.  While installing a radio in the car I dropped a penny in the cigarette lighter and blew a fuse.  Since then the car won't start at all the dash still lights up the motor works great but it just won't turn.

ANSWER: Ineed YEAR-MODEL-ENGINE SIZE.

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QUESTION: 1990 sedan deville,v8 engine 4.5 liter

Answer
Replace fuse #11 which is the center fuse in the top row of fuses in the fuse panel.

If replacing this fuse does not resolve your problem. You have your aftermarket radio wired incorrectly and have damaged the electronics within the vehicle which will cause the engine not to start. Your ONLY resolution is to take the car to a professional radio installer and have them wire it correctly.

The original radio has 3 different voltage wires going to and from the radio and if you wire the aftermarket radio incorrectly by using a test light to find your positive voltage source you may have wired the positive radio wire to the 5 volt or 12 volt or 26 volt wire in the radio wiring harness.