L345DT glow plug problem

[acroson]

I am having an issue with the glowplugs getting power when not cranking.

According to the manuals, diagrams, it should send 12 volts to the plugs when key is on and/or cranking.
mine only puts 6-7 volts when cranking to the plugs.

in my thinking, the starter switch is bad.
or do they only get 6 volts? I haven't been able to find a solid answer on the voltage output to the glowplugs.

otherwise our 345 is unstoppable.

thanks

 

[007kubotaguy]

Hello
You should have 12 volts to the glow plugs. What is the problem you are having. If you are getting 6 volts at the glow plugs , try removing the wire from the glow plugs and check voltage. I would also remove the jumper wire between the glow plug and check each one.
Good Luck Lance

 

[100 td]

I am having an issue with the glowplugs getting power when not cranking.

EDIT: When I wrote this, I missed the "NOT" cranking bit. It's still relevant, and you should do the same checks. I'll check the wiring diagram a bit later and update if need be.

IIRC the plugs get a little less than battery terminal voltage when applied by themselves due to the series glow plug heating coil/indicator on the dash.
When you are cranking your battery volts may drop a few volts due to starter current, so your plugs will see less as well, there will also be some voltage drop in the wiring to them. When you are cranking your dash indicator should not be in circuit so that the plugs get whatever voltage is available while cranking. If your battery is a bit poor, it's terminal voltage while cranking may get down to ~7 volts.
Do a few checks when you have a second battery with booster cables attached.

 

[100 td]

After checking the wiring diagram here , as previously noted when NOT cranking, your dash indicator should be in circuit and will heat up as the current for the glow plugs pass through it. In doing so there is a voltage drop across the element, I don't know what it is on your model but it may be as much as 1~4 volts, and you also have losses in cabling etc.. When you turn to start, the power should be applied to the other terminal of the switch and your plugs get full voltage, that voltage is dependent on your battery and your wiring. The contacts in your start switch could also be wearing out and not making good contact which would also cause some local heating and some more voltage drop.

So I'd suggest the same, check wiring and connections, the switch and measure voltages with a booster battery attached to ensure your existing battery isn't dropping too much under load.

On some Toyota diesel vehicles they employ a similar system, and fit 7 volt glow plugs. When glow is selected the current runs through a series intake heater before the glow plugs to reduce the applied voltage to the plugs, and when cranking the heater is switched out of circuit so that the plugs get full voltage, which is probably about 9 volts allowing for cable losses and volt drop at the battery due to high current cranking.

 

[rbargeron]

.....According to the manuals, diagrams, it should send 12 volts to the plugs when key is on and/or cranking........in my thinking, the starter switch is bad.......

With the key on, turning the large black switch to the left powers the glow plugs. They are also powered when the starter is running (switch turned right). If turning left doesn't run the glow plugs the switch needs attention.

 

[100 td]

@rbargeron do you by chance have a full service manual, does it also cover the L285?

 

[rbargeron]

I use my friend's Kubota WSM for his L355ss - which is nearly the same tractor as my L345. No coverage of other models unless you happen to find a component that's common to both in the parts lists.

 

[Mondo]

100 ...... I have a large WSM that covers 9 L models the L185. 235. 245,275, 285,295,305,345,and the 355. I don't know how to upload here and I don't come on but once a week or so. If you need it and I don't reply quickly don't think I'm ignoring you.