The story:
1999 seville sls. drove it all day never had problem with car turning over. after driving it for 45 min. I got out at a store and when went to go start the car. NOTHING. i mean go to turn to start and makes no noise, no atmpt to crank.everything works fine unitl I go to start the car thenall dash lights go dead, except check engine light. Ok battery right.voltage showed 14.6but the battery did so a drop in cranking amps when put on tester, replaced battery. nope still wont do anything...tried the park/nuetral thing, no security issues light goes away,no codes...OK, i said maybe a relay ...changed out the ingnition and starting relays...nope

Made the Stupid call to Cadillac...explained what happened they said probably the starter $900 for them to do it..( ya go bang it Cadillac)..IF NOBODY KNOWS THE STARTER IS INSIDE THE ENGINE....under the plenum..wow what a job that is.First romove wires,throttle body,un hook water pump and pulleys,drain coolant,remove fuel lines and fuel injectors, replace gasket and pray to god you dont crack the plastic plenum. (starter cadillac $320-Auto Zone $150) a ya i didnt do it yet....so I played with the keys and tried about 30 times just flipping from on to start quickly and about the 45th time it started. feeling lucky i shut it down and started it again no problem..sweet. Ishut offto put every thing back together. go to start car........nothing, did the key thing again and it started.

The question: Could it be the ignition switch, is there an inline fuse that might be faulty,bad computer not sending a signal to start,is it a dead spot in the starter. help please

 

Ignition switch is possible, check for 12v on purple wire at two wire connector at front edge of rear valve cover when car wont start.If 12v. on purple wire trouble between connector and starter. No 12v, there are 2 starter relays in under hood electrical to check out.