560 sl 86 alterator or OVP RELAY problem

[RICHR]

I have problem with my 560sl 86 .The batterary is dead but i charge it and engine runs for 10 to 15 mins then stops .The last time i drove it the tech jumped up tp 4000 rpms when i was only going 25 miles per hour .Also the pully is making noise on the alterator.
Where should i start replace alterator and what else . I here talk about OVP (Overload Protection Relay) Then the ABS relay .I checked all cables and they are fine.I located the OVP under dash .
Richard r rpba55@hotmail.com

[compress ignite]

1.Is the Alternator Pulley loose on the shaft?
2. Do you have (and know how to use) a "Multimeter"?
(Inexpensive at Harbor Freight (Less than $12.00 USD)
(Place appropriate leads on the Battery posts [meter set to D.C. Volts] with
the engine running...Should be somewhere between 13.5 and 14 Volts.You're
testing the Alternator's voltage output at idle.)

(To Quote Arthur Dalton) "Report Back".