Dynamo help...

[EpicDadof4]

Hello all! New here, I have a very old b6100 HST-D that hasn't charged the battery in years. I got motivated this weekend on doing some other maintenance and decided to tackle this. Without the battery attached, I was reading zero voltage at the battery terminals at idle. I decided to take the dash off and access the regulator the best I could and still zero volts on any terminal. I could finagle my fingers down in the front and tried to pull apart the terminals that connect two wires to the Dynamo to test there. As I mentioned, it's pretty old and I didn't want to pull any harder than I was in fearing I would yank the wire out of the terminal so I didn't get them apart, but noticed there were only two wires. And looking further I found a third wire not attached to anything. Then end is broke clean off and you can see a small copper wire. It has thicker insulation than normal and it's relatively stiff. It appeared to follow the same bend-path as the other two to the Dynamo and the length put the end into the silicone protection sleeve. I cut the tube back pretty far and couldn't find a third wire. It's black, but the wiring diagram show it should be rouge... I've attached a couple of pictures and can send more. Would just like to not have to get out the jump box every time...
Thanks in advance!!
Tim

 

[Russell King]

Dynamos won’t put out much voltage at idle. And I think there are two wire and three wire versions on Kubota’s. I have no idea how to test one but here is a link to someone that supposedly does know.

Testing a Tractor Dynamo and Regulator

Andrew Chapman guides you through the process of testing a dynamo and regulator for your tractor. Are you restoring a vintage, antique or modern tractor? Get top tech tips from our contributors. This article focuses on testing a dynamo for your tractor.

www.anglo-agriparts.com

Here is a thread that discusses both the two and three wire dynamo tests and shows the wiring on one of them.

b1500dt where is alternator

alternator/charge warning light stays on for a long time.

www.orangetractortalks.com

Good luck!

Edit: had to add the link to OTT thread

 

[North Idaho Wolfman]

Dynamos won’t put out much voltage at idle. And I think there are two wire and three wire versions on Kubota’s. I have no idea how to test one but here is a link to someone that supposedly does know.

Testing a Tractor Dynamo and Regulator

Andrew Chapman guides you through the process of testing a dynamo and regulator for your tractor. Are you restoring a vintage, antique or modern tractor? Get top tech tips from our contributors. This article focuses on testing a dynamo for your tractor.

www.anglo-agriparts.com

Here is a thread that discusses both the two and three wire dynamo tests and shows the wiring on one of them.

Good luck!

That's a good read for alternators what he's calling a dynamo, but it's not of any use to a Kubota dynamo.

 

[North Idaho Wolfman]

You need to twist the connections while pulling to disconnect them.
Or find the other ends of the wires and disconnect them at the regulator.

The dynamo should produce around 30 volts AC at full rpm.

Sounds like someone has swapped the dyno out for a three wire dynamo, that won't matter.

 

[Russell King]

That's a good read for alternators what he's calling a dynamo, but it's not of any use to a Kubota dynamo.

Oh I guess I should have read it before posting that link.

I added the missing link to the OTT thread that I had mentioned.

 

[EpicDadof4]

You need to twist the connections while pulling to disconnect them.
Or find the other ends of the wires and disconnect them at the regulator.

The dynamo should produce around 30 volts AC at full rpm.

Sounds like someone has swapped the dyno out for a three wire dynamo, that won't matter.

Thanks Wolfman. Electrical is not my best subject so I thought it was a typo when I first saw someone post AC voltage. Well, testing a second time revealed 30VAC at full throttle coming into the regulator so I guess I found my problem.

Thanks!!!