Tx Jim
New Member
Sounds as if alt pulley is worn out. When V-belt goes too deep in the pulley it looses grip. Is the bottom of the pulley groove shiny?
VR...working or not?
- Thread starter DFB
- Start date
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DFB
Elite Member
- Joined
- Dec 7, 2000
- Messages
- 2,897
- Location
- Southern VT, Southern ME
- Tractor
- John Deere 4100 HST /410 FEL, R4s
BobRip
Elite Member
The purpose of the alternator is to keep the battery charged. If it is doing that with normal loads then everything is ok. The alternator will not keep up with all your loads on at idle. Voltage drops with these loads particularly at idle.
Is your battery charged? Check with a hydrometer. If it is and continues to be charged then it is probably ok.
I have not heard you say if you are having starting problems. If you are not then it is probably ok.
Have you checked for battery discharge current with the engine not running? It should be below about 5 ma. To do this you have to disconnect one lead on the battery and put the current meter between the terminal and post. Everything must be off prior to this test. If you have high discharge current then the battery will run down while sitting. This is a touchy test and can damage or blow a fuse in your meter. I like to disconnect the terminal, put a jumper between the terminal and post, connect the meter, wait five seconds and then disconnect the jumper. This protects the meter from high initial currents. This is a rare failure.
The other rare thing is one diode blown in the alternator. The alternator will still function, but not put out full rated current.
Is your battery charged? Check with a hydrometer. If it is and continues to be charged then it is probably ok.
I have not heard you say if you are having starting problems. If you are not then it is probably ok.
Have you checked for battery discharge current with the engine not running? It should be below about 5 ma. To do this you have to disconnect one lead on the battery and put the current meter between the terminal and post. Everything must be off prior to this test. If you have high discharge current then the battery will run down while sitting. This is a touchy test and can damage or blow a fuse in your meter. I like to disconnect the terminal, put a jumper between the terminal and post, connect the meter, wait five seconds and then disconnect the jumper. This protects the meter from high initial currents. This is a rare failure.
The other rare thing is one diode blown in the alternator. The alternator will still function, but not put out full rated current.