Kubota L3710 glow plug light comes on when running, intermittent issue

[JJT]

About a week ago my 25 year old Kubota L3710 started having an electrical problem, the glow plug light on the dash would come on, (I'm guessing the glow plugs were also on). After a few seconds the light would go off. This happened a few times over the course of several hours of brush hogging. I did a little research and it seems the glow plug relay or the glow plug controller are the culprits. I ordered both parts, ($33 delivered on ebay, or $230 plus shipping from a large on-line Kubota dealer.....). I planned to replace both units since since the biggest project/pita is the dash removal.

Contrary to a YouTube post you don't need to disconnect the tach. There was enough slack in the tach, ignition wires, kill switch, etc, nothing needed to be disconnected other than the two part dash. There is a bolt inside the dash in the center that need to be removed. I put a little dielectric grease on the contacts. From start to finish less than an hour, with 90% of the time removing and re-installing the dash. Small hands would be an asset for this job but I got the job done with my size 12 mitts.

So far the issue seems to be resolved, I brush hogged for two hours with no glow plug light issue. If the problem comes back I'll spring for the pricy OEM parts.

 

[OhioJoe]

Same thing happened to me about 5 years ago. I replaced the controller which fixed the problem. I added a toggle switch between the controller and glow plug relay so I can turn off the glow plugs if it happens again. I was concerned the glow plugs would burn up as my light would not go off once it came on unless the key was turned off. These problems only seem to occur while we are too busy to stop and fix.

 

[NoTrespassing]

About a week ago my 25 year old Kubota L3710 started having an electrical problem, the glow plug light on the dash would come on, (I'm guessing the glow plugs were also on). After a few seconds the light would go off. This happened a few times over the course of several hours of brush hogging. I did a little research and it seems the glow plug relay or the glow plug controller are the culprits. I ordered both parts, ($33 delivered on ebay, or $230 plus shipping from a large on-line Kubota dealer.....). I planned to replace both units since since the biggest project/pita is the dash removal.

Contrary to a YouTube post you don't need to disconnect the tach. There was enough slack in the tach, ignition wires, kill switch, etc, nothing needed to be disconnected other than the two part dash. There is a bolt inside the dash in the center that need to be removed. I put a little dielectric grease on the contacts. From start to finish less than an hour, with 90% of the time removing and re-installing the dash. Small hands would be an asset for this job but I got the job done with my size 12 mitts.

So far the issue seems to be resolved, I brush hogged for two hours with no glow plug light issue. If the problem comes back I'll spring for the pricy OEM parts.

Small hands help working on the dash wiring. I had my wife plug in the key switch for me last weekend and I didn't even have to remove a dash screw! I replaced the glow plug controller and relay in 2014 on my L3710.