My Generac Guardian 15,000 Watt Model 004582 generator is putting out low voltage (about 45V on the 120V side). The trouble lights on the voltage regulator are lit as follows: Regulator light - lit red Sensing light - lit yellow Excitation light - blinks green Is the regulator bad? Jake Orfanello [email protected]

Hi Jake and welcome to FixYa. I am Kelly. Check both CB1 and CB 2 circuit breakers by pushing them to OFF and then back ON. Open the brush block access and then start the unit. You should read voltage at the brushes of 5 - 14 VDC on the terminals of the brushes. If you do not have 5 - 14 VDC at the brushes the probable suspect is the automatic voltage regulator (AVR). If you do have the correct voltages then with the unit OFF.... do a resistance check across the armature coil by reading resistance at the brush block terminals. You should read around 180 Ohms. It can be more or less resistance but for sure less than 500 Ohms. If you do NOT get a resistance reading remove the brush block assy and test the armature directly by reading across BOTH slip rings. You should get the resistance previously stated. If you have resistance then most likely there is a problem with the brushes. (Too short / broken carbon brush / missing spring or a defective terminal.) Without knowing the AVR output voltage and the armature resistance reading at this point it is difficult as to how to advise you to proceed. Let me know the values you obtain for AVR DC voltage at the brushes and actual ARMATURE resistance reading. Make sure you use R x 1000 on the meter. I am having thoughts of maybe a broken wire somewhere inside the control panel also.

Thanks for choosing FixYa,
Kelly