Mercedes Repair Questions? Ask a Mechanic for Answers ASAP
Hello,Replacing the belt should have made the alternator work, without the battery warning message. There is no reset. Possibly the alternator's wiring was damaged by the broken belt, or the alternator's regulator has failed
Hello Stan checked the wiring and charging all OK what do you think
The regulator seems to have failed. Does the message disappear if you rev the engine to 2-3000 rpm?
No and the regulator seems OK . have check output on tick over and at 2000 rpm and is being controlled OK at 14.75 volts. What do you think
Just check to see if it would go off as you sujested and tryed it at all sorts of reves up to 4000 rpm still no luck.
are there any voltage messurments l can talk for you to make an asesment
I would need the VIN to determine the alternator/regulator installed on your car.
Hello the vin number is *****
Hello,Click here for the wiring diagram of the ECU and alternator
When alternator is not charging - there must ground at the pin 1 of the 2-pin plug on the alternator. When charginng- there should be positive.
This signal is used to activate the warning message in the cluster.
I recommend to have the faults checked with Star Diagnosis computer as well, because the charging warning is triggered as a computerized signal from SAM to instrument cluster.
I do think it is strange that it was ok up to the point of the belt breaking when it obviously came on so you would expect when the new belt was fitted it would go out not require a test program on it. I have not disconnected the battery yet do you think that may switch it off
Disconnecting the battery is worth a try, since SAM sends a CAN signal to cluster. It might reset the SAM. Otherwise, the alternator works in the classic way.
terminal 61 operation check would tell if regulator works as it should.
I will try and report back
Will be glad to hear from you whenever it's most convenient for you
Stan disconnected the battery and reconnected light went straight out and all seems to be working OK.