RTV 900

[Calvinandhobbs]

Battery light was on when driving. Battery was dead next morning so charged on bench charger over night. Volt meter reads 14.8 on the battery. Put it back on and started up. The volt meter reads 15.8 when running and battery light still on. So is alternator or battery bad.

 

[Roadworthy]

Welcome to TBN. From your description it sounds like you've lost a diode in the alternator. A charged battery starts your rig. The alternator is putting out volts, though perhaps a bit high. The alternator light is still on. I'd pull the alternator and take it to visit and alternator repair shop.

 

[Calvinandhobbs]

Thanks. Will have it tested

 

[diesel85]

Welcome! I like your handle btw.

 

[Calvinandhobbs]

 

[JWR]

Welcome to TBN. From your description it sounds like you've lost a diode in the alternator. A charged battery starts your rig. The alternator is putting out volts, though perhaps a bit high. The alternator light is still on. I'd pull the alternator and take it to visit and alternator repair shop.

Yeah, assuming your meter is good the bare battery not connected ought to read very close to 12.0v. While charging it should read about 13.8v or so (high enough above 12 to facilitate charging.) I don't think it ought to ever read 15.8v. I agree with Roadworthy about getting the alternator tested.