KX36-3 Alternator wiring - Help!

[NeilB183]

Hello

Ive recently purchased a 2006 Kubota and am realsing now that it has a few issues unfortunately.
The battery does not charge and when investigating further i found 2 wires taped up hidden in the loom by the alternator that presumably once came from somewhere...
The alternator has a 3 connection plug and is missing one wire plus the oil switch is not connected so by my logic one wire must go to each, question is which?
One wire is blue, the other black. The alternators 2 wires that are still connected are Yellow/Red and green.

,

Any help would be much appreciared!

Thanks
Neil.

 

[Dave_eng]

See marked up photo.

 

[NeilB183]

Thanks Dave, I guess that black wire is maybe not heavy enough then, so I will dig around to see what else is taped up.
Do you think there should only be 2 wires to the alternator plug then?

Cheers
Neil.

 

[Dave_eng]

Thanks Dave, I guess that black wire is maybe not heavy enough then, so I will dig around to see what else is taped up.
Do you think there should only be 2 wires to the alternator plug then?

Cheers
Neil.

Neil
Unfortunately I have no experience with KX macines.

Some alternators put out a signal that is used for the tach on some tractors.

More photos from other angles might help.

The alternator output terminal appears to have remains of a crimp on terminal under the nut

In your supplied photo I see heavy wire(s) below the alternator. If one of these wires has the other half of a broken crimped on terminal then that would be the one for the main output.

Dave

 

[UpNorthMI]

I have a newer KX040, I just looked in the workshop manual and it shows a total of 3 wires for the alternator:

Thick wire (8 mm area cross section) - Red
1.25 mm area cross section - Yellow / Red stripe
0.75 mm area cross section - White / Red Stripe

So based on comments above I'm suggesting you are missing the heavy wire to the terminal connection - maybe Red wire. The smaller 2 wire connector seems correct.

My oil switch is shown as a 0.75 mm area cross section - Red wire.

Hope some of this helps.

 

[BruceP]

It may be easier if you figure out which is the OIL sensor wire to eliminate it from the mix.

First, we need a couple questions answered:

• Does your tractor have oil LIGHT or GAUGE?
• Does your OIL sensor have just a single wire? (if not, how many wires?)

If it is LIGHT and sensor has single wire.... It may be trivial to use an ohmmeter from an OIL pressure light to each of the wires to determine which one is correct.

 

[GreensvilleJay]

obtain a WSM ( WorkShop manual) for your new miniex !! You may be able to get a free one online, if not, buy it. You'll need it to really see WHAT wires are wrong/missing/busted.
For sure the main charge wire from alternator is 'mia'. The plastic wire loom has black tape on it . Maybe OEM ,maybe not...real close to manifold though.... maybe burned wires inside ??
My guess is someone had the alternator off( replaced belt ??) and broke 'stuff',never got around to properly fixing it (diesels run a long time on battery...)
One of those hard to fix long distance, might be a simple 10 minute 'here's what's wrong' if in person though.

 

[NeilB183]

Thanks for all the advice. Looks like somebody messed around with this quite a bit...
You were right, I cut open the taped up loom and found the fat red wire for the alternator, plus a black and a white wire which ive reconnected to the temperature sensor.
The original blue went to the oil sensor and the black/white stripe one was the third wire missing/snapped from the 3 pin plug. So far so good, oil and battery lights now come on and go off and i presume once warmed up the temp gauge should move.

BUT before connecting the big red to feed the battery, I tested the voltage on the bolt connection (output) on the alternator. It gives out 0V until you apply max revs, it then goes up to 17V, but when you drop the revs back to tickover it goes UP to 18V. I would have thought this a bit high to charge the battery? Is it that the alternator maybe needs replacing?
Thanks guys!

Neil.

 

[GreensvilleJay]

GREAt picture and progress!!

Connect the red wire up. without a battery( load) the reading is not accurate. I'd need to see the schematic, but 'most' alternators need some kind of 'feedback' to work properly. The 'idiot light' aka 'broken fan belt' is used on lots but unknown how that alternator works.
Reading 15-18 volts is OK, least it isn't totally busted !
Slip on red wire, small, flat washer, then the nut. The flat washer keeps the wire from turning while you tighten the nut.
Also, I'd rerout the wiring so that it can't get near that exhaust manifold, 2" away would be great. just be sure it can't,over time, creep onto it..

 

[thebicman]

It's great your finding out where all the wires go. My concern would be why were they all disconnected. If everything works then why?

 

[GreensvilleJay]

I was thinking 'busted fan belt' replacment......
if it's anything like the one on my forklift, it's a REAL PITA.....
one fo those..ok mr 'engineer' YOU show me HOW it's done...
step one...get a NEW box full of bandaids....
step two, WAIT unti engine is stone cold...
step thre.. the real 'fun' begins....

 

[Dave_eng]

I looked through some Kubota WSM's and believe your alternator has a output signal to the tach.

The only alternators utilizing the 3 wire plug have this rpm function.

This piece from the BX2380 WSM may help sorting out the wiring.

Dave

 

[NeilB183]

Thankyou all for the great info and advice.

Cant understand why anyone would have chopped all the cables like that, doesnt make any sense to me, but heh ho, pleased to report that with all connections remade everything seems to be working. Hurrah!

Many thanks
Neil.

 

[whitetiger]

Thankyou all for the great info and advice.

Cant understand why anyone would have chopped all the cables like that, doesnt make any sense to me, but heh ho, pleased to report that with all connections remade everything seems to be working. Hurrah!

Many thanks
Neil.

Here is a pdf of the wiring diagram for your KX36-3.

 

[FTG-05]

Thanks for all the advice. Looks like somebody messed around with this quite a bit...
You were right, I cut open the taped up loom and found the fat red wire for the alternator, plus a black and a white wire which ive reconnected to the temperature sensor.
The original blue went to the oil sensor and the black/white stripe one was the third wire missing/snapped from the 3 pin plug. So far so good, oil and battery lights now come on and go off and i presume once warmed up the temp gauge should move.

BUT before connecting the big red to feed the battery, I tested the voltage on the bolt connection (output) on the alternator. It gives out 0V until you apply max revs, it then goes up to 17V, but when you drop the revs back to tickover it goes UP to 18V. I would have thought this a bit high to charge the battery? Is it that the alternator maybe needs replacing?
Thanks guys!

Neil.
View attachment 70056

Don't run the engine with the alternator unconnected to the battery. It's an excellent method for destroying the alternator. As noted above, it needs to the battery feedback to produce the proper voltage.

 

[GreensvilleJay]

Please explain HOW you can destroy the alternator if left unconnected .