If your Mercedes® is cranking slowly when starting and the lights are dim even when you're revving your engine, it may be time to replace the alternator. We offer Bosch and other O.E. factory rebuilt units. Alternators are rebuilt to meet rigid factory specifications. When ordering a rebuilt unit, the applicable (depending on application) core charge is added to your order automatically. This core charge will be refunded in full when we receive your core in a good rebuildable condition. Return freight on the core is the customer's responsibility. (For refund we must receive your core within 30 days)