Glow plug light not working

[Jsaon41]

The other day I went to start my L35 and the glow plug light didn't come on. The machine started without issue but I thought it odd. There wasn't the relay click or drop out either. The other normal prestart dash lights came on but no glow plug. Is this the machines way to tell me the glow plug is shot? Or could it be a relay buried under the dash? Is there a way to test the plug?
Any thoughts?

 

[North Idaho Wolfman]

It's not one Glow Plug it's 3 on your model (one per cylinder).
The issue could be as simple as a blown fuse, bad relay, burned out glow plug or plugs, bad wiring.
If your normally hearing a click of a relay when the glow plug light is on, and right now your not, then I would focus on a blown fuse and then the possibility of bad relay or wiring.

 

[lugbolt]

The glow plugs on those tractors run off of a controller behind the dash. The controller works off of the coolant temp sensor. If coolant temp is cold, the controller senses it and triggers the glow plug relay to stay on longer than if it was hot coolant.

That said, it's not uncommon for the controller to die. Sometimes the relay, but more frequently the controller. To my knowledge, there is not a tried-and-true test for it. When I diagnose one, I'll test the relay, wiring, and the coolant temp sensor. If all those are ok, the controller's usually shot.

 

[seann]

The glow plugs on those tractors run off of a controller behind the dash. The controller works off of the coolant temp sensor. If coolant temp is cold, the controller senses it and triggers the glow plug relay to stay on longer than if it was hot coolant.

That said, it's not uncommon for the controller to die. Sometimes the relay, but more frequently the controller. To my knowledge, there is not a tried-and-true test for it. When I diagnose one, I'll test the relay, wiring, and the coolant temp sensor. If all those are ok, the controller's usually shot.

Do you know where the controller is on an RTV 1140 and a part #?

 

[Technical Ted]

Does anyone know how cold the coolant has to be for the glow plugs to activate? I've got a L3560 and have never seen the glow plug symbol on my dash, but I don't think I've ever stored it where it was less than ~45 degrees F.

Thanks,
Ted

 

[sheepfarmer]

Does anyone know how cold the coolant has to be for the glow plugs to activate? I've got a L3560 and have never seen the glow plug symbol on my dash, but I don't think I've ever stored it where it was less than ~45 degrees F.

Thanks,
Ted

I think they may be active during the time that the welcome Kubota stuff is flashing across the display, and you don't see the glow plug symbol to wait longer until it is pretty cold, I think it was 18F or so. You may never see yours if the tractor is inside above 45.

 

[dmac]

would that temperature sensor cause my control relay for the glow plugs to be missing a ground. it has 12 volts when I turn the key to the on position but no ground.

 

[CountryBumkin]

would that temperature sensor cause my control relay for the glow plugs to be missing a ground. it has 12 volts when I turn the key to the on position but no ground.

I don't know the specifics on your tractor model, but it is possible that that coolant sensor is a actually a coolant "switch" (open when hot, closed when cold) in that case the relay could use the switch as its ground.

 

[Technical Ted]

I think they may be active during the time that the welcome Kubota stuff is flashing across the display, and you don't see the glow plug symbol to wait longer until it is pretty cold, I think it was 18F or so. You may never see yours if the tractor is inside above 45.

Thanks!
Ted