Glow Plug Light

Trkr

Member
Feb 7, 2015
51
1
8
Baltimore County,Md
Hi guys,I have new to me L2900.Tractor runs great,but the glow plug light/timer seems to have a mind of its own.Sometimes when I start it cold,light comes on briefly like it's supposed to_Other time it comes on and stays on for several minutes,till I shut the tractor off and restart it.It has also come on after its been running a while,and same thing,I shut the tractor off and restart it to get the light to go out.Glow plugs seem to work good,this thing will start easily in constant below freezing weather.I've done a little searching here,but I want confirm my problem before I spend the money.Do I need a glow plug controller?If so,where is it,and how much are they?Thanks.
 

Stubbyie

New member
Jul 1, 2010
879
0
0
Midcontinent
Not intimately familiar with your machine; others here can furnish schematics and parts diagrams...

First is to eliminate as possible culprits bad wiring, key switch, other switch, bulb, loose connections, chaffed wire providing intermittent short-to-ground----the simple and relatively inexpensive possibilities.

Next consider the controller may be exhibiting temperature related intermittent problems.

Try making a deal with your dealer to try a replacment controller and if doesn't rectify the problem return it. Some dealers will, some won't. If you're careful and handy you can jumper connections from tractor to controller box and get a test without actually 'installing' it (remember to use one jumper as 'chassis ground' from box shell to tractor).

I think you'd benefit from using an inexpensive analog needle-type multimeter in your trouble-shooting of wires and switches.

My controller is under dash, right of steering wheel, and cost abouit $70 couple years ago. In my case the glow plug lamp would stay on continuously with key 'on': the system was keeping the plugs energized continuously too and for that reason the alternator couldn't keep the battery charged to keep up the power used continuously by the plugs.

Please post back your continuing experiences so we may all learn.
 

Diydave

New member

Equipment
L2202 tractor, L185f tractor
Oct 31, 2013
1,636
1
0
Gambrills, MD USA
I second the notion of checking for loose connections, particularly at the glow plug end. Seems that with the heat, the buss bar between the plugs tends to loosen up...:D
 

Confused8122

New member

Equipment
L3600
Oct 26, 2014
10
0
0
Marquette, mi
I have a L3600GST, and it had the same symptoms. The glow light would come on whenever, and stay on for as long as it felt like. Sometimes it wouldn't come on at all. When it didn't come on, it was harder starting.
After some research and diagnosis, I determined that my glow controller was bad. I read the wiring diagrams and decided it wasn't worth paying for a new one. I wired a heavy duty momentary switch to the glow relay, and also the glow light.
Now instead of an automatic glow plug, I turn my key on, push and hold button for however long I feel is necessary, then start the tractor. Cost me about $5, and half hour of time. It would have taken me as long to replace the controller, but I spent much less money.
 

Trkr

Member
Feb 7, 2015
51
1
8
Baltimore County,Md
I have a L3600GST, and it had the same symptoms. The glow light would come on whenever, and stay on for as long as it felt like. Sometimes it wouldn't come on at all. When it didn't come on, it was harder starting.
After some research and diagnosis, I determined that my glow controller was bad. I read the wiring diagrams and decided it wasn't worth paying for a new one. I wired a heavy duty momentary switch to the glow relay, and also the glow light.
Now instead of an automatic glow plug, I turn my key on, push and hold button for however long I feel is necessary, then start the tractor. Cost me about $5, and half hour of time. It would have taken me as long to replace the controller, but I spent much less money.
Thanks for the idea,sounds like a winner to me!
 

Kingcreek

New member

Equipment
Grand L3010 GST 4wd, LA481FEL, various attachments and accessories
Aug 3, 2011
453
0
0
NW Illinois
I had the same thing. Replaced the GP controller, about $70 and less than 1 hour and its working perfect. I didn't mind doing the proper fix since it was the first part failure of any kind in 14 years/1150 hours of service beyond routine maintenance.
 

Service Dept Vic

Moderator
Staff member
Vendor Member
Feb 15, 2009
2,512
2
38
Southern Alberta Canada
You guys are great Kubota Service Tech Diagnosticians!

I too would be following a trouble shooting repair flow chart starting with loose electrical then chaffed wiring going to earth and ending with the possibility of a faulty/intermittent glow plug timer/relay.

Opposite of what Donald Trump would say--"You're all hired"!
 

Confused8122

New member

Equipment
L3600
Oct 26, 2014
10
0
0
Marquette, mi
Just to clarify, my relay was good, but my controller was bad. The controller gives ground to the relay to power the glow plugs. It also grounds the indicator to turn it on. I cut the two ground(control) wires, and hooked to a grounded momentary switch.
That way I didn't completely remove the controller, it would be easy to revert back to factory. And the controller won't make the indicator come on all the time.
 

Trkr

Member
Feb 7, 2015
51
1
8
Baltimore County,Md
Just to clarify, my relay was good, but my controller was bad. The controller gives ground to the relay to power the glow plugs. It also grounds the indicator to turn it on. I cut the two ground(control) wires, and hooked to a grounded momentary switch.
That way I didn't completely remove the controller, it would be easy to revert back to factory. And the controller won't make the indicator come on all the time.
Thanks!Understood.
 

hackw1rm

New member

Equipment
L3600 GST
Mar 30, 2015
5
0
0
Jackson, MI
Im having this same issue, glow plug light comes on and stays on. During use the light will continue to go on and off. Thinking this might also be draining my battery because it continues to die on me. Is yours still working correctly or did another issue arise?