Great Plains Aircraft
Supply Co.


1. This alternator will fit all Great Plains/Diehl accessory cases. On accessory cases made prior to 11/89, some machine work will be necessary.

2. On cases prior to November, 1989, the hole in the accessory case where the wire from the stator comes out of the accessory case will need to be machined in a new spot. Simply line up stator with the four 10/32 holes that it bolt to and you will see where the new hole for the stator wire will need to be machined into the case.

3. The next check involves assembling the stator to the case and the magnet ring to the flywheel (flywheel must be installed on the engine). With this done, slowly mate the accessory case to the engine bellhousing. The accessory case may not bolt down firmly against the bellhousing. We have found that on cases prior to 11/1989, it has been necessary to machine between .025" and .090" off of the area on the accessory case that the stator bolts to.

4. The regulator/rectifier is one unit. This unit must not be put in an environment where the temperature will operate over 180° F. continuous. The cooler the better. Most failures of the regulator/rectifier are simply caused by heat. FINS MUST BE VERTICAL.

5. To hook up your system, simply connect the two wires to the outside terminals of the regulator and the center terminal goes to the positive side of the battery through a switch.

6. This alternator will not produce a lot of electrical power at idle. It needs to be spun at a minimum of 1500 rpm to produce electrical current.

7. The regulator/rectifier unit must be properly grounded to the alternator. Simply placing the unit on standoffs located on the firewall may not be sufficient. A ground wire may be necessary.

8. These units have been spun tested prior to shipping.

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