RepairPal Certified shops can diagnose and repair your 1990 BMW 525i. They provide transparent pricing with a minimum 12-month or 12,000-mile warranty on repairs and services.
Possible that your charging system is wearing out. Need to have battery and alternator tested to be sure they are producing enough power. Get code read at a parts store and post the result on here.
lite goes off when you shut off ac so no stored code