Kubota D1105 3 Cylinder glow plug voltage what should it be

[DJthebigfella]

Hi i have a kubota f2400 from mower with a D1105 3 cylinder. It wont start and i checked the voltage to the glow plugs and i am only getting 9.5 volts. I dont think this is enough to heat up to start it. What should the voltage be on the glow plugs please?

I have 12 v to the plug but when i engage the glow plugs to heat them i only get 9.5v. Would a bad plug cause this voltage drop.

I have checked them as stated in the manual and resistance is good and individually they with 12v they tested and glowed ok but when in the motor the voltage drops to 9.5v

Any advice would be much appreciated thanks in advance.

 

[GreensvilleJay]

Start at the battery !
What's it's voltage before you start and then after 5 minutes of 1500 RPM running ?
How old is the battery ?
What's the CCA of it?
Ever been 'load tested'?
Have you removed/cleaned/inspected the battery cables ?
Have you removed/cleaned/inspected the Glow Plug wires ?
Is the GP control circuit a switch or a 'computer' ?
What's the air temperature ?

Normally a 'lead acid battery' will read 13.2 volts when fully charged, at 70*F.
Glow plugs will draw 10 amps ,each( 3 x 10= 30 amps).
A small resistance of 0.1 ohms between battery and glow plugs, will 'drop' 3 volts ( 0.1 x 30 ).
That's why wiring MUST be in GREAT condition!

 

[InTheWoods]

I wouldn't be alarmed at seeing 9.5V at the glow plugs. But, why are you checking it in the first place?

 

[Russell King]

There is a glow plug indicator (resistor) on my L185F that drops the voltage. BUT I do NOT see a similar device on your F2400. It may be inside an electrical box on your tractor.

That drops the voltage down but only to around 10.5 to 11 volts. I think your voltage is low to the glow plugs but I also note that the glow plugs on yours cost ~$60 each while my glow plugs are around $12 each.

Here is a simple test that bypasses the indicator on my tractor. The glow plugs get power during the crank cycle of the start. But the starter drops the voltage down if it is cranking. So on my tractor the clutch pedal must be pushed down for the starter to spin. So if that is the same on your tractor, just don’t push the clutch down and see how many volts are at the glow plugs.

I recommend getting a wiring diagram and workshop manual if you can get them. That way you will know what voltage you should be getting.

 

[DJthebigfella]

I wouldn't be alarmed at seeing 9.5V at the glow plugs. But, why are you checking it in the first place?

Hi there the machine was not starting only started after i put 12v on the glow plugs and then it ran rough one injector is not performing as it should. it would not start other than doing this thanks for your help.

 

[DJthebigfella]

There is a glow plug indicator (resistor) on my L185F that drops the voltage. BUT I do NOT see a similar device on your F2400. It may be inside an electrical box on your tractor.

That drops the voltage down but only to around 10.5 to 11 volts. I think your voltage is low to the glow plugs but I also note that the glow plugs on yours cost ~$60 each while my glow plugs are around $12 each.

Here is a simple test that bypasses the indicator on my tractor. The glow plugs get power during the crank cycle of the start. But the starter drops the voltage down if it is cranking. So on my tractor the clutch pedal must be pushed down for the starter to spin. So if that is the same on your tractor, just don’t push the clutch down and see how many volts are at the glow plugs.

I recommend getting a wiring diagram and workshop manual if you can get them. That way you will know what voltage you should be getting.

 

[DJthebigfella]

There is a glow plug indicator (resistor) on my L185F that drops the voltage. BUT I do NOT see a similar device on your F2400. It may be inside an electrical box on your tractor.

That drops the voltage down but only to around 10.5 to 11 volts. I think your voltage is low to the glow plugs but I also note that the glow plugs on yours cost ~$60 each while my glow plugs are around $12 each.

Here is a simple test that bypasses the indicator on my tractor. The glow plugs get power during the crank cycle of the start. But the starter drops the voltage down if it is cranking. So on my tractor the clutch pedal must be pushed down for the starter to spin. So if that is the same on your tractor, just don’t push the clutch down and see how many volts are at the glow plugs.

I recommend getting a wiring diagram and workshop manual if you can get them. That way you will know what voltage you should be getting.

Hi Russel i do need to engage the clutch to start so i will try that i do have workshop manual but i cant seem to find the voltage 9.5 v is definitely to low and without a boost it will not start. i do have a electrical control box its only small from the wiring diagram the only wire to the glow plugs is from the starter switch. the glow plugs took a while to glow when tested and the fuel injectors have been glowing at some stage signs of high heat on the injection end. Will let you know how i go thanks for your advice much appreciated.

 

[DJthebigfella]

I wouldn't be alarmed at seeing 9.5V at the glow plugs. But, why are you checking it in the first place?

Hi there i could not get it to start at all no matter what i did, only started when i put good voltage onto the glow plugs thanks for your help,

 

[DJthebigfella]

Start at the battery !
What's it's voltage before you start and then after 5 minutes of 1500 RPM running ?
How old is the battery ?
What's the CCA of it?
Ever been 'load tested'?
Have you removed/cleaned/inspected the battery cables ?
Have you removed/cleaned/inspected the Glow Plug wires ?
Is the GP control circuit a switch or a 'computer' ?
What's the air temperature ?

Normally a 'lead acid battery' will read 13.2 volts when fully charged, at 70*F.
Glow plugs will draw 10 amps ,each( 3 x 10= 30 amps).
A small resistance of 0.1 ohms between battery and glow plugs, will 'drop' 3 volts ( 0.1 x 30 ).
That's why wiring MUST be in GREAT condition!

Hi Jay will check it all mate thanks i know my battery is shot but i have been jump starting it off a good battery maybe that is the problem thanks for you help

 

[DJthebigfella]

Start at the battery !
What's it's voltage before you start and then after 5 minutes of 1500 RPM running ?
How old is the battery ?
What's the CCA of it?
Ever been 'load tested'?
Have you removed/cleaned/inspected the battery cables ?
Have you removed/cleaned/inspected the Glow Plug wires ?
Is the GP control circuit a switch or a 'computer' ?
What's the air temperature ?

Normally a 'lead acid battery' will read 13.2 volts when fully charged, at 70*F.
Glow plugs will draw 10 amps ,each( 3 x 10= 30 amps).
A small resistance of 0.1 ohms between battery and glow plugs, will 'drop' 3 volts ( 0.1 x 30 ).
That's why wiring MUST be in GREAT condition!

Hi Jay the battery in the machine is no good i have been jump starting it off a good battery maybe that is part off my problem wants to go but just wont fire all check all the wiring again thanks for your help

 

[GreensvilleJay]

If you jumpered the BAD battery with the good one, that's a real bad procedure...
The bad battery can drain down the good one,so you'll not get a good '12 volts'.
Remove the bad battery...Use jumper cables to temporarily connect good battery to tractor if the good batteries too big, wrong size or posts are backwards.

 

[Russell King]

Hi Russel i do need to engage the clutch to start so i will try that i do have workshop manual but i cant seem to find the voltage 9.5 v is definitely to low and without a boost it will not start. i do have a electrical control box its only small from the wiring diagram the only wire to the glow plugs is from the starter switch. the glow plugs took a while to glow when tested and the fuel injectors have been glowing at some stage signs of high heat on the injection end. Will let you know how i go thanks for your advice much appreciated.

You might want to see how much voltage you are getting at the key switch into the switch and then out of the switch to the glow plug. Not sure if you have a key switch with terminals (easy to test) or with a wiring connector (which makes it harder to test it installed)

But put a good battery and good cables and clean the ground point well. It is amazing how many things that can fix.

 

[DJthebigfella]

If you jumpered the BAD battery with the good one, that's a real bad procedure...
The bad battery can drain down the good one,so you'll not get a good '12 volts'.
Remove the bad battery...Use jumper cables to temporarily connect good battery to tractor if the good batteries too big, wrong size or posts are backwards.

Thank you very much Jay mate will do i know the battery is bad thanks