How to

[gaul 0]

How do i wire up the electrial system on a AC 720 with the original Onan engine to make the charging sysyem operational, without the original rectifier and regulator?

[Guest]

Depends on what devices you are using for the rectifier & regulator?

[gaul 0]

What are the devices I need to use in place of the rectifier and regulator?

[Guest]

I'd like to know that one myself. Anyone?

[StanD 0]

The rectifier can be replaced with a full wave rectifier available at a good electonics store for roughly $10.00. I use a 300 volt 35 amp unit and find it far more solid than the original. Still has to be bolted to the frame to dissipate heat, has 1 bolt hole & can be mounted using one of the original holes. The regulator can be made using electical components. That project is far more involved. Myself, I continue to use the original regulator. The weak point I normally find is corroded connections to the ignition switch & the ignition switch itself. I use relays such as Al sells to carry the heavy loads such as the charging circuit & clutch circuits. This puts a very small load on the ignition switch itself & eliminates the arcing & burning that you normally find on the switch & plug. These relays can be applied on any tractor to lessen the load on the switch. StanD

[gaul 0]

That figures, I would have the one you can buy. I need the regulator. Can you buy it.

[JimS 1]

For information on doing electrical tests, go to "articles" under the "resources" menu, click on "electrical system", then click on "Troubleshooting Onan Charging Systems". You should also check the stator coil and flywheel magnet ring located behind the flywheel. If the magnet ring comes loose from the flywheel, it can cause a lot of damage. This is a common problem on these engines. You can see these parts if you take off the right side cylinder head shroud. You will have to pull the engine if they have to be worked on. The regulator is Onan part number 191-0939.