Glow plug light stays on

colt63

New member

Equipment
L3010
Apr 17, 2016
3
1
3
Columbia, Missouri
I have a L3010 Kubota - starts quickly runs real good. But the glow plug light stays on. Anybody know why and what would be the fix
Thanks
 

Kingcreek

Member

Equipment
Grand L3010 GST 4wd, LA481FEL, various attachments and accessories
Aug 3, 2011
457
2
18
NW Illinois
Welcome! I have a L3010 and the glow plug light would come on anytime it felt like it and sometimes stay on for quite awhile and got progressivley worse. Called the dealer and asked about glow plug controller or relay and the parts guy had a mechanic standing next to him. The verdict was gp controller. Purchased and replaced and no problem since. This was the first actual part failure on mine at about 1150 hours. Otherwise has been just routine maintenence. the gp controller was about $70 IIRC. pull the dash loose and it is just ahead of the "firewall" on the right side. Took me about an hour but I work leisurely.
 

GWD

Member

Equipment
M7040, L48 TLB, BX2200
Jan 8, 2010
792
15
18
Northern California
Got to agree. It is usually a relay.

My L48 would do the same thing. The light would stay on, go off, stay on longer (or shorter). In other words...erratic.

The parts diagram showed two controllers/relays. Rather than hoping and replacing just one, both were replaced. Glad I did it because tearing into the dash was a chore.

Anyway, the problem was cured and now the glow plugs work perfectly.

The issue with not fixing it in a timely manner is the likelihood that the glow plug(s) will burn out. Then you have a whole new problem along with the original. The old, "stitch in time..." saying applies.
 
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pmmully

New member

Equipment
Kubota 2006 L48 TLB
Feb 5, 2021
6
0
1
32952
Got to agree. It is usually a relay.

My L48 would do the same thing. The light would stay on, go off, stay on longer (or shorter). In other words...erratic.

The parts diagram showed two controllers/relays. Rather than hoping and replacing just one, both were replaced. Glad I did it because tearing into the dash was a chore.

Anyway, the problem was cured and now the glow plugs work perfectly.

The issue with not fixing it in a timely manner is the likelihood that the glow plug(s) will burn out. Then you have a whole new problem along with the original. The old, "stitch in time..." saying applies.
I believe mine are already burnt out. Got it what way used. It lives in the SE so not really a problem I guess.
 

Dave_eng

Well-known member
Lifetime Member

Equipment
M7040, Nuffield 465
Oct 6, 2012
5,235
1,017
113
Williamstown Ontario Canada
I believe mine are already burnt out. Got it what way used. It lives in the SE so not really a problem I guess.
You do not want hard ceramic pieces of failed glow plugs coming off inside your cylinders. These pieces do serious damage.

Why you you think they have already failed?

Dave
 

airbiscuit

Active member

Equipment
New Holland T2310, New Holland TC21D, Kubota l3010 GST, Farmall H
Mar 18, 2021
214
150
43
NW WI
I know this is an old thread recently bumped, but here is a good video about replacing the glow plug controller/relay.

 

pmmully

New member

Equipment
Kubota 2006 L48 TLB
Feb 5, 2021
6
0
1
32952
You do not want hard ceramic pieces of failed glow plugs coming off inside your cylinders. These pieces do serious damage.

Why you you think they have already failed?

Dave
I am just surmising as the light is constantly on. It just as easily is the controller.

I was told by many to not worry about the light being on constantly. Nowhere in the manuals does it say to service the glow plugs themselves. I bought it used with 1750 hours.
 

Dave_eng

Well-known member
Lifetime Member

Equipment
M7040, Nuffield 465
Oct 6, 2012
5,235
1,017
113
Williamstown Ontario Canada
I am just surmising as the light is constantly on. It just as easily is the controller.

I was told by many to not worry about the light being on constantly. Nowhere in the manuals does it say to service the glow plugs themselves. I bought it used with 1750 hours.
You don't want to just ignore symptoms that may be telling you important info.

At the very least, verify the GP's are not being powered regardless of the light being on.

A 12 volt test light for $15 can easily tell you this.

Connect the test lamp alligator clip to the battery negative and touch each GP with the test light tip. If as you think all is well the test light will not turn on.

Your choice to repair the controller or relay.

Test light.jpg


Dave