RepairPal Certified shops can diagnose and repair your 1994 Mercedes-Benz E420. They provide transparent pricing with a minimum 12-month or 12,000-mile warranty on repairs and services.
It won't be a relay concern. Have diagnostic testing performed to find out what is happening.
https://repairpal.com/repair-shops/mercedes-benz-repair-and-service-in-pittsburg-california