glenhenshaw
New member
- Joined
- Sep 5, 2011
- Messages
- 12
- Tractor
- 1973 John Deere 820 3 cylinder
Hi all,
I have a John Deere 820, serial number 065272L. I've owned it since 2005 and have used it sparingly. For several years now I've known it had a problem charging the battery. I'd put a new battery in it and it would start 5 or 6 times, and then I'd have to start jumping it; after ten or twelve more starts that wouldn't work either, since the car doesn't really provide enough current to turn the JD starter, so I'd put a new battery in it.. Since I only use it five or six times a year, this system worked okay.
But this week I couldn't start it for anything and so got serious about fixing it. At the suggestion of my local JD dealer (really small place in southern Maryland) I pulled the alternator and took it in to be tested. And... lo and behold, it looks for all the world like it's a six volt alternator; it even says "6V" on the service plate. Which explains why it won't charge a twelve volt battery, but leaves us with a couple of bigger mysteries. First, the alternator looks nothing like the alternators shown on the various OEM parts supplier websites for this tractor. Second, how and why did anyone get a six volt alternator that actually fits - there are no apparent modifications to the tractor to make the alternator fit - and install it in what is clearly a twelve volt electrical system?
The JD mechanic, who in my experience is very good, is scratching his head. He's afraid to order a replacement OEM alternator since they all look different from the one that came off the tractor, and can't figure out how you could even find a 6V alternator that would randomly fit the wrong tractor.
Any ideas?
I have a John Deere 820, serial number 065272L. I've owned it since 2005 and have used it sparingly. For several years now I've known it had a problem charging the battery. I'd put a new battery in it and it would start 5 or 6 times, and then I'd have to start jumping it; after ten or twelve more starts that wouldn't work either, since the car doesn't really provide enough current to turn the JD starter, so I'd put a new battery in it.. Since I only use it five or six times a year, this system worked okay.
But this week I couldn't start it for anything and so got serious about fixing it. At the suggestion of my local JD dealer (really small place in southern Maryland) I pulled the alternator and took it in to be tested. And... lo and behold, it looks for all the world like it's a six volt alternator; it even says "6V" on the service plate. Which explains why it won't charge a twelve volt battery, but leaves us with a couple of bigger mysteries. First, the alternator looks nothing like the alternators shown on the various OEM parts supplier websites for this tractor. Second, how and why did anyone get a six volt alternator that actually fits - there are no apparent modifications to the tractor to make the alternator fit - and install it in what is clearly a twelve volt electrical system?
The JD mechanic, who in my experience is very good, is scratching his head. He's afraid to order a replacement OEM alternator since they all look different from the one that came off the tractor, and can't figure out how you could even find a 6V alternator that would randomly fit the wrong tractor.
Any ideas?