M7040 glowplugs

Tx Jim · Dec 12, 2013

I would use a volt/ohm meter or test light and turn ign switch to on then see if there's any electricity to GP's. Problem could be fuse or relay.

suzy · Dec 12, 2013

Today was just hovering around the -2 or -1C, so didn't have my m7040 plugged in. With the key turned to the glowplug position, the green glowplug light came on for two or three seconds, then went out. Started right up. Came in at lunch time, now at 0C. An hour later, no glow plug light, but was probably still warm from the morning.

jcummins · Dec 12, 2013

suzy said:
Today was just hovering around the -2 or -1C, so didn't have my m7040 plugged in. With the key turned to the glowplug position, the green glowplug light came on for two or three seconds, then went out. Started right up. Came in at lunch time, now at 0C. An hour later, no glow plug light, but was probably still warm from the morning.

What year is your 7040...and is there positions with the key that are detents (stopping points) for off/on/glowplug/start? I sthe glowplug position between on and start?

I pulled the loader up high so I can better get under the hood today....but it's cold enough here I don't want to spend a lot of time in the cold. It was 5 degrees Fahrenheit this morning.

jcummins · Dec 12, 2013

Next week it suppose to get a bit warmer during the day....40s. Have an easier time working with it.

What controls the temperature that the plugs come on....the relay? I think I see the fuse, but where is the relay located
I'm wonder if the bulb may be burned out too. How do you get to it? Does the whole cowling have to come off? If it was nice and warm I'd be taking things apart, but prefer to not open up things unless I have to.

wmonroe · Dec 12, 2013

If the engine is cranking over slowly then you might have a separate issue, are the battery terminals clean? What about the cable connection at the starter? Is the battery the correct CCA?

big bubba · Dec 12, 2013

"Glow plug indicator comes on when the key is turned to "ON" position and engine coolant temp.is below O degrees C(32 degrees F) and goes off automatically when preheat is completed." tx jimmp

if operating correctly, the glow plugs will be indicated on dash (amber light) if coolant is below certain temp (32 degrees?). the length they remain on is according to how much below that temp. so if you say it's 5 degrees, will stay on longer than 32. if the engine turns slowly in that case, of course it could be the battery as you say, but also dependent on viscosity of engine oil. if it's 15/40, guarantee the engine will turn slowly @ 5 degrees. a lower rated viscosity range (ie 5/40 syn diesel rated) will turn over considerably easier. what grade oil do you have in it? good luck

jcummins · Dec 12, 2013

I've got Rotella 15w40 in it....and that has crossed my mine. Rotella makes a 5w40, I just may go to that given this issue. I've used the same 15w40 year round in my Duramax with 230K miles with zero issues and that's why I used it.

The battery seems good ..... but it may be the reserve in the battery. It is 700cca. I always oversize my batteries, and would prefer a 900cca. I do not know the spec the tractor calls for, and my manual is in the cold barn right now.

The point that no one has answered, is what is magical about the glowplugs coming on at 32 degrees, and what specially controls that? ALL and every other diesel I've had the glow plugs come on MUCH sooner than that.

big bubba · Dec 12, 2013

feel as though the slow cranking is oil related. esp @ 5 degrees. not familiar w/schematic, but there's a coolant sensor that triggers the plugs for however long. but you never said how how easily it starts aside from sluggish cranking, any problem? the glow plugs are doing their job. if you intend to regularly use it in these conditions, would opt for T6 if you want to stay w/rotella. (what i use)

jcummins · Dec 13, 2013

big bubba said:
feel as though the slow cranking is oil related. esp @ 5 degrees. not familiar w/schematic, but there's a coolant sensor that triggers the plugs for however long. but you never said how how easily it starts aside from sluggish cranking, any problem? the glow plugs are doing their job. if you intend to regularly use it in these conditions, would opt for T6 if you want to stay w/rotella. (what i use)

If it was truely 5 degrees...yes I would agree. It was 5 outside but in the unheated but insulated barn, think it was more like low 30s. The Gator and the Duramax sitting right next to the tractor does not crank like that.

If the glowplugs are working...then the light in the dash is bad, since it does not come on. Outside of the sluggish crank, the tractor does fire right up.

Perhaps I need to go to the trouble of taking the battery out and have it load tested....but I really don't think that is the problem.

wmonroe · Dec 13, 2013

Since the tractor is cranking slow while your truck and gator are not is what make me think you may have a battery or connection problem. There might still be an issue with the glow plugs not coming on but if the tractor is starting ok then maybe it just isn't cold enough.