W203 battery/ alterntor warning

[LINDS HANSON]

Getting the red warning message, checked voltage output at 14.5V alternator pulley looks fine, could this be a front SAM issue? No fault codes Thanks

 

[alexander patie]

short answer to short question, yes it could. that is maybe..

 

[AndyPCD]

It could also be the alternator regulator that has gone.
This would be a cheaper option before going for a front sam. Over the years i have never had a front sam go down and cause the warning light to come on on the dash

 

[alexander patie]

i have known this just once. changed front sams on these cars for loads of other reasons though. and they are around £250 now, and in stock at local dealers, ie a frequent seller!

 

[LINDS HANSON]

Sorry for being short just a bit frustrated with getting to a dead end at the SAM, I have 14.7v at the SAM and a running signal on curcuit 15 at the SAM, But how can one test the SAM output to instrument cluster? I guess this would be a Can signal

 

[alexander patie]

yes indeed, a can signal. is the warning message permanently displayed? if so you can be sure it is not an intermittent alternator fault.

 

[BlackC55]

14.7 is a little high actually