# Converting my Oliver 550 from a generator to an altenator



## jim warren (Jun 6, 2018)

I want to convert my Oliver 550 gas tractor to an alternator. An alternator is available at Yesterdays tractors but they couldn't tell me if it would fit the original generator brackets or if I needed some type of adapter kit. What else needs to be done to convert? The tractor is 12 V positive ground and I would like to change that to negative ground.
Thanks to anyone that can help.
my email is [email protected]


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## pogobill (Jan 31, 2012)

I believe you may need an alternator bracket kit. Here's a good article on conversions.
https://www.yesterdaystractors.com/articles/artint8.htm


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## Ed Williams (Jun 13, 2019)

I converted a1953 Ford NAA from 6v to 12v and the old generator to alternator. I used a 1976 Chevy 3 wire alternator, $30, for the conversion vs the 1 wire alternator, $70. With the 3 wire you have to add a diode to regulate voltage. This can be a side marker light, or if you have an automotive type ignition switch, hook the rhird wire to the acc terminal. With the one wire none of this is necrssary. You will have to build your own bottom base bracket. The kits do not fit and have to be altered anyway. I had to put the 2 bottom attachment lugs at an angle for the pulleys to line up, but used the original top adjustment bracket. Also, I mounted the original pulley from the generator on the alternator so I could use the original 5/8" Ford belt instead of going to a 1/2" belt. It was an exact fit, no modifications as shaft diameters are the same. Used the original 6v coil, but had to add 3 resistors in series to get the required 4 ohm resistance across the coil. Mounted these on a wood block where the origin as l voltage regulator was mounted. Do not need a voltage regulator with the Chevy alternator. Voltage is controlled internally in the alternator. All this info is available at "Yesterday's Tractors" website. They have a separate section on their website for 12v conversions, including wiring diagrams. Also available at several other Web sites. Just search " tractor 6v to 12v conversion. The only piece that required an advanced search was you can use the existing 6v coil if you adjust the resistance across the coil to 4 ohms. Resistors far cheaper than buying a new 22v coil. My total cost for the 12v negative ground conversion was less than $50. Starts in 2-3 revs every time. Will never go back to 6v. Don't forget to change light bulbs to 12v. FYI. 12v items are less than 1/2 the cost of 6v iiems.


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