proud owner of a 159
Join Date: Sep 2011
Location: United Kingdom
The voltage does look low should be up in the 14volts range when the engine is running even at idle the @ should be charging but modern alternates are SMART so charge on demand, yes check the drive belts and earth first although the belts multi rib and very reliable now and last ages , could be the tensioner but I think you would hear it slipping when you put all the electrics on , heated windows and main beam blower etc.
I have not fitted one myself but access looks difficult ? Anyone on here fitted one might be able to help.
Has the bumberhgot to be removed first ????????