B7100 Dynamo Wiring

[jc82chevyman]

So I got a new dynamo it has two wires coming off it instead of 3 like the old one, anybody have any idea how to hook up a regulator to it without going to kubota and shelling out $90.00 for it. I searched through threads and the common answer is to use a snowmobile regulator but I have access to a regulator off of old tractors just need to which wires go where.

 

[kubotasam]

On the 3 wire dynamo the light switch acts as a hi/lo charge switch (more charge when you turn on the lights). The 2 wire just charges a 1 rate and does not pass through the light switch. The both use the same regulator. The difference is the wiring between the dynamo and the regulator. You will need to rewire. Run 2 wires from the dynamo to the AC imputs on the regulator. I think they are the 2 blue wires. I have both wiring diagrams, just not in front of me now. If you need more help I can scan and send them to you.

 

[jc82chevyman]

The two wires coming off of the new dynamo are blue, the old one I think there was two gray ones and brown IIRC. So I guess Im going to have to work some magic

 

[kubotasam]

The two wires from the dynamo need to go to two wires on the AC side of the regulator(rectifier). You will need to run new wires or change the wiring that is already there to bypass the light switch. I don't have my books at hand or I would scan the 2 different wiring diagrams so you can see the difference. I hopefully can get them tonight and scan them tomorrow.

 

[Rob]

Is this any help Sir...

rob

 

[Rob]

or maybe this diagram.

rob

 

[tmessenger]

I have an older (1979) B7100 and it has the 2 wire alternator they work find. It puts out 9A @ 14v through the regulator when the battery is down and drops off to around 2A when the battery is charged.

 

[kubotasam]

Here is the 3 wire diagram. The light switch is actually 2 switches with one nob controlling both. With the 2 wire dynamo no wires go to G1, S, G2 on the light switch. Run the 2 wires from the dynamo to the AC leads on the regulator/rectifier. You should be all set.

 

[jc82chevyman]

Ok so I had a 3 wires yellow, brown and white. I found the brown wire went directly to the regulator so that was a no brainer. I traced the other two and found that the white and yellow wires went to the light switch and I then traced a red wire from the switch to the regulator. I found that the yellow wire continuity with the red wire when the lights were on so thats what I went with. However I need an amp gauge because with the machine running at high idle the fluke meter is only showing 12.6 volts, but the battery was a bit discharged so I have it hooked up wrong tell me so I can get it straightened out.

 

[kubotasam]

Did you bypass the light switch? With the 2 wire dynamo you can't use the white, yellow, or red wires unless you disconnect them from the light switch. You need one wire that goes from the other AC lead on the dynamo to the connection on the regulator where the red wire went.