I am working on the wifes 2002 S60 2.4 nonturbo. Having an problem the Battery keeps going dead. Had the alternator tested and it was putting out 14.2 volts untill a load was put on then it dropped to around 12.3 and the tester stated bad diode and weak regulator. My question is this I found that the single wire that conects to the voltage regulator broke could this cause the regulator to go bad and is the diode in the regulator. can the regulator be replaced or do i need a new alternator

 

The wire broke I believe is the signal to the CEM, these cars are known for bad regulators and the bad one will have a number, hard to see, but begins with 229, you may have to use a mirror, it will be a gold or white in color number if that is on there, replace the regulator if you like, it is cheaper and you do NOT have to remove the alternator.