Oliver 77 wiring diagram

Planning on putting a one wire alternator on the 77. Already has a 12 volt negative ground battery.......not my doing! Anyone have a simple wiring diagram? Thanks.

If it makes a difference it has a switch and a push button start. Thanks

I like the three wire best. No need to reeve it up to get it to charge. Just use a light or diode.

I totally agree with tractorcedric, you definitely don't want a 1 wire alternator. They are made for stationary engines that run for hours at a time at near max rpms. The 3 wire unit will charge at all rpms and will produce adequate voltage and current at an idle. If you need a schematic for the 3 wire (10si or 12si), let me know.

Just wondering why I have 2 folks saying not to use a 1 wire alternator on the Oliver? I have them on a Ford 640 and a Ford 960, both tractors get used a good bit. Both alternators start charging at low rpm. Is an Oliver different? Just curious, I'm not an electrical guy. Any clarification would be appreciated thanks

I don't know what to tell you on that. I never converted one from a generator. My 1550 has an alternator and the regulator went bad on that one. A one wire alternator was cheaper than a regulator,so I switched it. I just have to bump the throttle a little to get that one to charge. I had to put a toggle switch on it though so I can break the circuit because if it sat very long,it would drain the battery.

Since I assume you have to buy one anyway,you're going with the small alternator that'll fit up under the hood without cobbling for two days to make brackets then make five trips to town looking for the right length belt aren't you? Don't make the mistake that an old guy in our club made. He put one of those little one wire alternators on his 77 and it wouldn't charge. It had been positive ground with the original generator and he forgot to change it to negative.

If the generator is good on it I would prefer to leave it,but at this point it's sorta half and half. Would need 6 volt battery and bigger cables. Those cables cost way more than a alternator. Any size alternator will fit, I ain't got side panels... Or as little as I drive it ,just run a charger to battery every now and then.

I changed my 66 and 77 both to 12 volt generators. The brackets and wiring are direct bolt up swaps. Like I said,if you have to buy a new one anyway,I would certainly go with the smaller alternator just for simple installation and the chance that you'll come across a cheap set of side curtains some day.

Well.....I am still looking for curtains.......lol. where would I look for a 12 volt generator? I like the look of it better than an alternator.

Any tractor regardless of the brand built between about 1957 and 1965 or so would have had a 12v generator. Any Oliver diesel and I assume other brand diesels built anytime before 65 or so would too. Any tractor parts supplier including YT should have 12v generators and the saddle type regulators that bolt on top like the original 6v on that 77.

Thanks.

This is a generic diagram. Your starter activation and switches may be different but this will give alternator hookup. Use just the output with one wire alternator

I'm one of the guys that mentioned not to use a 1 wire alternator if possible. This thought pattern comes from years of tech experience and hands on alternator swaps. The folks that replied to your thread didn't mention whether they had diesel tractors or not. Diesels normally have large batteries to comp for cold weather and stiff oil conditions and with a 1 wire attached you can make several starts in a short period of time and not notice reduced cranking power. I personally wouldn't put a 1 wire on any tractor not just an oliver 77. I really like the 14.7 volts and 75 amps delivered instantly to the battery and respective accessories with a 3 wire. The real key is the sense wire from the 3 wire connected directly to the battery at the ammeter. For instance, after a hard/cold start I want to see the ammeter leaning hard to the plus side until it sees the batt has reached 14.7vdc. The 1 wire will eventually get you there after some time, but the battery may not even reach 13 volts, not very bright lights here. A good running charging system needs a large wire from the alternator to the battery, 10ga minimum.

I have a small ford diesel 2600 that we rake hay with sometimes 24 hrs non-stop for my 1 month season. The ford has a 1 wire installed by the previous owner and I still have to charge it almost daily to keep the lights bright, no leds here but lots of standard lights and the 1 wire won't keep the battery at 13.5 volts at night. The PO chopped up the original harness so bad I have been putting off the swap to the original 3 wire.

If your Oliver 77 is going to be a puller you defiantly want 14 volts at your coil resistor for max power. I have seen many a puller fall short because the cooling fan sucks the battery to 10.5 volts near the end of the pull. This is because they have a small light weight battery and 1 wire alternator. I like to see the battery slammed to its working voltage immediately.

Thank you! Excellent information. And we'll written. Even this carpenter could understand it! This 77 won't be a puller. Just something different in Alabama to take to shows. It may be worth leaving it alone for now and just charging battery as needed. Won't be driving it much. Probably need a 12 volt coil. I think it's a 6 volt

If you haven't found a 12v generator by the next time I come down there I'll bring you one and you can have it. I bought 6 of them at Dale Tibbe's sale last fall for $10. I'll never use that many.

Rrlund, y'all coming down for this end if the longest yard sale? I would be more than happy to pay for a generator and shipping, if not ...... Let me know. Thanks! I would much rather have a generator on there, just looks better.

I wanted to come down this year,but as of right now,my nephew is supposed to get married on August third. He's been with her about as long as he's ever been with one before he finds a reason to break it off,and she has put on a few pounds since they started shacking up,so who knows if it'll happen or not. If you want to send me an email,I can look these over and see which one looks best. You'd just have to buy one of those saddle type regulators to put on it. You can get those most any place tractor parts are sold.

Rrlund. [email protected]. Let me know what I owe you for it and I will get a check headed your way. Thanks!

I answered your email.

1 of the best threads I've read here...I'll be keeping this one.