OK here is the problem I have 1998 SLS, I just had to have new head gaskets installed and new inserts for the head bolts it cost me about $2500. I got the car back and the alternator needed new bearings, so they said the regulator was bas too( There was no problem with charging the battery before!). Now when I start the car up the Service Security System is displayed on the information window, then the speakers crack and there is no volume on the radio. The security lite is also on at this point. After ther runs for about five miuntes the security lite goes off and everything is fine. I did notice my battery voltageranges from 15.2 to 14.9. It never did that before it was always 14.0. Please help!

 

I have the same problem with my seville too, when I put my alarm in, the security light came on. i dont know how to fix it!! i need help too