Sebculb
Gold Member
Hola everyone,
Would anyone know anything about things that can cause an alternator to repeatedly cook itself? '97 JD 310D backhoe. The alternator is relatively new, perhaps six months. I bought it from the expensive commercial electromechanic shop because they have the parts on hand and are pretty knowledgeable, if very expensive. A couple weeks ago my machine wouldn't start, batteries were dead. Checked the alternator, wasnt charging. Took it to the shop, $50 later they gave it back with new brushes and bearings, and it was charging again. Batteries wouldn't stay charged, so I got a new battery. (down to one big battery from two smaller batteries).
Charged the new battery for a bit before installing just to make sure, 12.7 volts. Checked for a drain on the system at the negative terminal just out of curiosity, and it was registering a 12.7 v drain with the machine turned off, tracked it to the alternator. Not enough amperage in the drain to turn on a bulb-style circuit tester though. Took the alternator back to the shop, they replaced a $20 diode or plate or something and gave it back to me. Still had the same drain. They said it's always gonna be there, something about a condenser or something and that the amperage is negligible on a battery. Vocabulary is translated from spanish, we're in Costa Rica.
Machine started great, strong turnover, charging at 14+ volts. Dug a small ditch at my house, couple days later went to do another job nearby. That day smelled the hot electrical smell while working, touched the alternator and it was hot enough to give me a blister burn on my hand. Let the machine cool down a bit, disconnected the alternator and drove home on battery power. Alternator was always charging but clearly not right.
Now they "fixed" it again and charged me $200. This is starting to be a pain in the ***. This time they replaced the regulator, diodes, plate and one phase of the bobbin. remember, spanish translation if it doesn't make sense. The people at the electromechanic shop say that only battery related things can do it, that if were caused by a short circuit it would register a significant battery drain while the machine is turned off. They're saying my old batteries that wouldn't accept a charge cooked it the first time and that my new battery has a defect or something and is low on charge or something and that's what cooked it this time. They got a "specialist" from a local battery shop to come and check the acid levels and he said they're low, I left it at his shop so he could do more extensive testing overnight. I'm sure they're all in cahoots.
The battery is a big 950 amp Mack battery from the local CAT dealer, can't imagine that's the problem but exhausting all their explanations before raising ****. However, if they were trying to give me a runaround, I'd expect them to tell me that my hoe's hodgepodge electrical sytem is short circuiting and that's to blame. That would be a definite possibility because previous owners have done who knows what with it, most fuses aren't connected to anything. However, the alternator shop says that's not really a possible cause.
Anyone have any insight? sorry for the long winded explanation but figured it's better to know the whole story.
Thanks!
Would anyone know anything about things that can cause an alternator to repeatedly cook itself? '97 JD 310D backhoe. The alternator is relatively new, perhaps six months. I bought it from the expensive commercial electromechanic shop because they have the parts on hand and are pretty knowledgeable, if very expensive. A couple weeks ago my machine wouldn't start, batteries were dead. Checked the alternator, wasnt charging. Took it to the shop, $50 later they gave it back with new brushes and bearings, and it was charging again. Batteries wouldn't stay charged, so I got a new battery. (down to one big battery from two smaller batteries).
Charged the new battery for a bit before installing just to make sure, 12.7 volts. Checked for a drain on the system at the negative terminal just out of curiosity, and it was registering a 12.7 v drain with the machine turned off, tracked it to the alternator. Not enough amperage in the drain to turn on a bulb-style circuit tester though. Took the alternator back to the shop, they replaced a $20 diode or plate or something and gave it back to me. Still had the same drain. They said it's always gonna be there, something about a condenser or something and that the amperage is negligible on a battery. Vocabulary is translated from spanish, we're in Costa Rica.
Machine started great, strong turnover, charging at 14+ volts. Dug a small ditch at my house, couple days later went to do another job nearby. That day smelled the hot electrical smell while working, touched the alternator and it was hot enough to give me a blister burn on my hand. Let the machine cool down a bit, disconnected the alternator and drove home on battery power. Alternator was always charging but clearly not right.
Now they "fixed" it again and charged me $200. This is starting to be a pain in the ***. This time they replaced the regulator, diodes, plate and one phase of the bobbin. remember, spanish translation if it doesn't make sense. The people at the electromechanic shop say that only battery related things can do it, that if were caused by a short circuit it would register a significant battery drain while the machine is turned off. They're saying my old batteries that wouldn't accept a charge cooked it the first time and that my new battery has a defect or something and is low on charge or something and that's what cooked it this time. They got a "specialist" from a local battery shop to come and check the acid levels and he said they're low, I left it at his shop so he could do more extensive testing overnight. I'm sure they're all in cahoots.
The battery is a big 950 amp Mack battery from the local CAT dealer, can't imagine that's the problem but exhausting all their explanations before raising ****. However, if they were trying to give me a runaround, I'd expect them to tell me that my hoe's hodgepodge electrical sytem is short circuiting and that's to blame. That would be a definite possibility because previous owners have done who knows what with it, most fuses aren't connected to anything. However, the alternator shop says that's not really a possible cause.
Anyone have any insight? sorry for the long winded explanation but figured it's better to know the whole story.
Thanks!
