Repeated alternator failure on Kubota D1105T engine on my loader backhoe

   / Repeated alternator failure on Kubota D1105T engine on my loader backhoe #1  

westcliffe01

Veteran Member
Joined
May 16, 2009
Messages
1,296
Location
SE MI
Tractor
Kubota M4500DT, B200 backhoe
I bought my Superstav EF2 (Bobcat B200) loader backhoe 2003 model with about 1400 hours on it in 2009. In 2010 the alternator failed. The stator was fine, diodes were good, brushes were good and ultimately we found that the field winding was open circuit. This is the winding that is on the rotor with which the current output of the alternator is regulated.

So I bought a replacement on Ebay (exact same Denso alternator) and today while moving dirt a little more than 150 hours after replacement, the battery lamp came on.....

The only thing I can say is that the alternator seems to get really hot. It has the radiator in front of it, no integral fan and the turbo is above and directly behind it. I don't know whether the heat from the turbo or radiator is the culprit, but a new alternator every 150-200 hours does not sound like a long term plan.

Anyone else have any issues with their alternator on the D1105 series engines ?
 
   / Repeated alternator failure on Kubota D1105T engine on my loader backhoe #2  
I feel you have another issue that is causing the Alternator to have to work on overdrive! Do you have some heavy eletrical use that is drawing while the machine is running?
 
   / Repeated alternator failure on Kubota D1105T engine on my loader backhoe #3  
...perhaps a chafed wire that's grounding...
 
   / Repeated alternator failure on Kubota D1105T engine on my loader backhoe
  • Thread Starter
#4  
Sorry, I have not been back in a while. There is not much electric on the machine. It has a fusebox and nothing has blown. The things that are powered up when it is running is the electric diesel lift pump, the safety solenoid which enable the hydrostatic drive and the fuel shutoff valve on the injection pump. The only instrumentation is the water temperature, oil pressure switch (normally open when there is oil pressure), and fuel tank level.

I need to investigate what goes on with the ignition switch, since it seems the problem is intermittent. Since it is intermittent, it seems that the alternator itself is probably still good.
 
   / Repeated alternator failure on Kubota D1105T engine on my loader backhoe #5  
i too think it is an excessive load or battery with bad cell..
 
   / Repeated alternator failure on Kubota D1105T engine on my loader backhoe
  • Thread Starter
#6  
Its a battery less than a year old. It can crank and crank that engine when its cold, so no performance issues with the battery.

I suppose I need to get a current clamp so that I can check how much current is flowing and in which circuit.
 
   / Repeated alternator failure on Kubota D1105T engine on my loader backhoe #7  
put an inline ammeter with the alternator.. they are way cheaper than a dc current clamp
 
 
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