I had the same problem with my Renault Trafic Van.
Checked just about everything with a meter & no other symptoms, no voltage drop & Alternator charging fine.
I happened to be by the front of the van very early the other morning & heard a feint 'buzzing' sound from the front of the van.
After further investigation, I removed the Battery + cable from the Alternator & the noise stopped.
Fitted a new Alternator & now all is fine.
Posted 13 Jan 2012, 21:04
#5