I have a massey 240 and looks like the alternator is not charging my battery. There are some 2 wires connected to the alternator and not sure if these are enough to allow the battery to get charged once i start the tractor, is the anything i need to do so that battery gets charged once i start the tractor
Alternator not charging my battery
- Thread starter Willsk
- Start date
seville009
Veteran Member
- Joined
- Oct 22, 2007
- Messages
- 1,532
Check the alternator belt first; make sure it’s not slipping.
With the engine off, check the battery voltage- should be roughly 12.5 or 12.6
Then start the engine and check yhe battery voltage again - should be roughly 13.6 to 14.6.
If the voltage doesn’t change (go up) while the engine is running, then the alternator is not charging it.
If that is the case, probably the easiest thing to do is take the alternator off, and take it in to be tested. If the alternator is old, may also be just as easy to simply replace it.
Note - I am assuming that the battery itself is known to be good. If your initial battery reading while it is off is in the 11’s, then the battery itself may be bad and can’t take a charge anymore. If that is the case, put a new battery in before messing with the alternator, as that nay fix everything.
With the engine off, check the battery voltage- should be roughly 12.5 or 12.6
Then start the engine and check yhe battery voltage again - should be roughly 13.6 to 14.6.
If the voltage doesn’t change (go up) while the engine is running, then the alternator is not charging it.
If that is the case, probably the easiest thing to do is take the alternator off, and take it in to be tested. If the alternator is old, may also be just as easy to simply replace it.
Note - I am assuming that the battery itself is known to be good. If your initial battery reading while it is off is in the 11’s, then the battery itself may be bad and can’t take a charge anymore. If that is the case, put a new battery in before messing with the alternator, as that nay fix everything.
Slowpoke Slim
Elite Member
- Joined
- Jan 6, 2017
- Messages
- 3,766
- Location
- Bismarck, ND
- Tractor
- Husqvarna YTH24V48 riding mower, Branson 3725CH
Can't answer the question on "how many wires", without knowing things like (a shop manual with a schematic would be "gold" here):
Single field or double field alternator
Internally or externally regulated
Have the battery load tested first, if the battery tests good, then take the alternator in to be tested. Many times alternators can be rebuilt, if you have a motor (as in electric motor) repair shop, or similar near you. If the alternator is internally regulated, the "alternator" could be fine, and the regulator could be bad. Rectifiers (part of the "alternator" part) can also go bad. A good repair shop can completely rebuild the one you have now, including new bearings.
Roadworthy
Elite Member
Seville009 has given some really good information. Besides a slipping fan belt you may have worn out brushes in the alternator. Worn brushes may allow the alternator to put out the correct voltage when there's no load but drop under load - like charging a battery.