b1500dt where is alternator

[dave gardener]

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

 

[85Hokie]

You checked belt that drive it?

You place meter on battery BEFORE starting and after starting?

When you say long time........ like seconds or the entire time of use?

 

[dave gardener]

You checked belt that drive it?

You place meter on battery BEFORE starting and after starting?

When you say long time........ like seconds or the entire time of use?

I tried tensioning belt but I think tensioning pulley is fully out. It was last year I think meter showed no change when motor running but I'm going to retry to refresh my memory. Charge light goes out after about 15-20 minutes. Can't seem to figure out where alternator is. Thanks for your expertise.

 

[RCW]

I’m not sure, but would venture a guess that your tractor doesn't have an alternator, but instead a dynamo.

A dynamo generates AC voltage, which is then converted to DC through a rectifier to charge the battery.

Lot of folks think a dynamo is a water pump. Belt pulley driven.

Also guessing your tractor doesn't have a water pump, but uses a thermosyphon.

Here are some good references for Grey Market tractors, if you haven't seen it before.

Ultimate gray market must read | OrangeTractorTalks - Everything Kubota

 

[dave gardener]

I’m not sure, but would venture a guess that your tractor doesn't have an alternator, but instead a dynamo.

A dynamo generates AC voltage, which is then converted to DC through a rectifier to charge the battery.

Lot of folks think a dynamo is a water pump. Belt pulley driven.

Also guessing your tractor doesn't have a water pump, but uses a thermosyphon.

Here are some good references for Grey Market tractors, if you haven't seen it before.

Ultimate gray market must read | OrangeTractorTalks - Everything Kubota

Just heading out to where the tractor is now and will check out some things you mentioned. Thank you for your wealth of information.

 

[RCW]

I’m scarcely a wealth of information, but quite a few folks here are.

If you post some pictures of the engine it may help. I don’t see a similar US version of the B1500.

 

[85Hokie]

DYNO is located here - see if there are 2 wires that come out of this - use a volt meter and set it to AC and test those two leads ........... yes - engine needs to be running and be careful doing it!!!

If you have 25+ volts AC then the dyno is working ( 3/4 or better throttle)

Dynos rarely go bad - the bearings go bad but most live the life of the tractor.

 

[RCW]

Guessing if charge light is on it’s something with rectifier or wiring to/from rectifier to battery.

Again, I’m guessing.

 

[dave gardener]

DYNO is located here - see if there are 2 wires that come out of this - use a volt meter and set it to AC and test those two leads ........... yes - engine needs to be running and be careful doing it!!!

If you have 25+ volts AC then the dyno is working ( 3/4 or better throttle)

Dynos rarely go bad - the bearings go bad but most live the life of the tractor.



View attachment 137979

Yes, that looks like mine. Looks like there's three wires coming out of mine and then tapping into another cable which I don't know which leads me to two other directions so I will have to trace it out. I would also like to replace the belt but not sure how the tensioner actually works. I don't know if you have to first loosen a bolt through the center of the pulley and then use that little adjusting bolt on the side?

 

[dave gardener]

I’m scarcely a wealth of information, but quite a few folks here are.

If you post some pictures of the engine it may help. I don’t see a similar US version of the B1500.

 

[85Hokie]

Loosen the one marked "L" and then back off the one marked "T"

I believe the 3 rd wire goes to the light circuit.......... if/when lights are turned on the dyno needs to put out more AC to the rectifier.

 

[dave gardener]

Loosen the one marked "L" and then back off the one marked "T"

I believe the 3 rd wire goes to the light circuit.......... if/when lights are turned on the dyno needs to put out more AC to the rectifier.

View attachment 137994

Hey that's great. I'm going to replace the belt with maybe one size smaller as the tensioning is maxed out right now and maybe that'll do the trick for it. Maybe is slipping on the Dynamo.

Loosen the one marked "L" and then back off the one marked "T"

I believe the 3 rd wire goes to the light circuit.......... if/when lights are turned on the dyno needs to put out more AC to the rectifier.

View attachment 137994

Hey that's great. I'm going to replace the belt with maybe one size smaller as the tensioning is maxed out right now and maybe that'll do the trick for it. Maybe is slipping on the Dynamo.

 

[Russell King]

I believe the 3 rd wire goes to the light circuit.......... if/when lights are turned on the dyno needs to put out more AC to the rectifier.

If I recall correctly the head lights may be fed directly by the AC voltage from the dynamo

 

[dave gardener]

If I recall correctly the head lights may be fed directly by the AC voltage from the dynamo

Yeah just trying to figure out how I can access my test leads to some terminal points for those two leads you said to check the voltage.

 

[North Idaho Wolfman]

Yeah just trying to figure out how I can access my test leads to some terminal points for those two leads you said to check the voltage.

There is connectors from the dynamo on the left side of the engine just forward and above the starter.

 

[dave gardener]

There is connectors from the dynamo on the left side of the engine just forward and above the starter.

I thought these might be them but they almost look like they're heat shrinked.

 

[North Idaho Wolfman]

I thought these might be them but they almost look like they're heat shrinked.

Those are bullet connectors.
To test a three wire Dynamo, you test with an AC multi meter between each pair, so you will get three values.

 

[dave gardener]

Loosen the one marked "L" and then back off the one marked "T"

I believe the 3 rd wire goes to the light circuit.......... if/when lights are turned on the dyno needs to put out more AC to the rectifier.

View attachment 137994

Got lucky for once. I took your advice on how to adjust the tension from your picture and it all makes sense once you do it once and there was still room to tension so it took maybe not even a quarter of a turn of tensioning and the alternator light or charge light extinguished. I always overthink everything and make think it's going to be so complicated from a new Dynamo or at worst case get another belt which I think should be easy to get on and off on this model. But thanks to you it was a breeze. Thank you very much.