Help! L3240 won't start when cold

[bferris01]

HI,

Thanks for the help.

I have a 2010 L3240-HST-3 and this is the first issue I have had with it and need some help. So when the temp's dropped this season it began to give me issues with starting in the cold. I did some internet search and found some starting ideas to check but now I am stumped. I will say when the outside temps are not cold it starts and runs fine, I have tested the battery and it is fine. So here is the situation when temps are down:

-Try to start by cycling the glow plugs 2-3 times and it cranks over but won't start, get a white-ish smoke from the exhaust
-pulled the dash and there are 2 relays behind the instrument panel, 2- identical relays. I pulled the 1st one to look at it and there was some discoloration on the spade, so I replaced it with an autozone relay and when that didn't work bought a OEM Kubota relay and same result, no start white -ish smoke
-pulled all the fuses in the fuse box down by the clutch petal, and that all look good.....

Really needed the tractor to water the animals so I took a wire and jumped the relay and it started right up with only 1 cycle of the glow plugs and ran fine, it was turned off after running for 10-15 mins and then started right back up no problems a few times until done for the day.

I can deal with jumping the relay for a little while but the wife will not and needs to use the tractor when I am at work for 48hr at a time.

So I am stuck, it will be a major pain in the A$% to have to arrange to get it to the dealer and was hoping someone might have some experience or thoughts on something else to check.

Stay safe and warm and thanks for any thoughts.

 

[The Fred]

There was a run of machines where Kubota installed the wrong glow plug and fuel solenoid relays.

You have to pull the dash to check both. The terminals are supposed to be large but they installed smaller than specified relays with small terminals that won't make contact when cold.


Good luck, Fred

 

[bferris01]

Fred, Thanks... I discovered that when I got the OEM relay from Kubota, so it currently had the new bigger terminals. I had hoped that would fix it, but even with the new one installed same outcome.

 

[The Fred]

Can you hear that relay click or come on when you turn the key? You could have a bad controller. Try using a test light to see if the relay is even coming on.

Regards

 

[bferris01]

Can you hear that relay click or come on when you turn the key? You could have a bad controller. Try using a test light to see if the relay is even coming on.

Regards

Yes I hear the click and the glow plug indicator comes on as it always did. I put a meter on it and get 12v from 1 leg with the key off, and nothing in the other legs, then turn the key to glow plug position and get 12v from 2 legs ( I believe as it should). I also swapped with the other relay and get the same results.

Thanks for trying.

 

[The Fred]

So the instrument cluster is the controller for the glow plugs, it finishes the ground for the glow plug relay primary circuit. This circuit is fused 7.5 amp so make sure that fuse is not blown. If the instrument cluster is not providing a ground to the relay you could have a bad coolant temperature sensor. Is the coolant temp gauge working ok? Does it seem accurate?

I have the complete manual in pdf form but it is too big to email you. Are you sure the relay holder didn't get burned up where the relay plugs in? 70 plus amps is big push through a relay with improperly sized terminals.

Regards, Fred

 

[bferris01]

Fred,

Thanks, for the info. I didn't know the cluster was the control. I have been searching and searching ....lol guess that's why I didn't find a seprate "box".

I double checked the 7.5 fuse and it is good. The temp gauge on my cluster is just a bar graph, and seems to be working fine. I don't see any melting or burn marks in the holder and it does start when I insert the jumper wire so I think it is fine.

I now have the upgraded OEM Kubota relay with the bigger copper terminal.

 

[jeff9366]

KUBOTA COLD START VIDEO: Winter cold start tips - YouTube

 

[moship]

Yes I hear the click and the glow plug indicator comes on as it always did. I put a meter on it and get 12v from 1 leg with the key off, and nothing in the other legs, then turn the key to glow plug position and get 12v from 2 legs ( I believe as it should). I also swapped with the other relay and get the same results.

Thanks for trying.

You should have battery voltage at two of the relay terminals.

Based on your description, you’re not getting the high current power to the glow plugs. There is a 50 amp slow burn fuse for this side of the circuit.

From WSM

Glow Relay
1) Connector Voltage
1. Turn the main switch off.
2. Disconnect the glow relay (1).
3. Measure the voltage across the terminal 1 (Positive) and
chassis (Negative).
4. If the voltage differs from the battery voltage, the wiring harness
is faulty.
5. Turn the main switch on.
6. Measure the voltage across the terminal 3 (Positive) and
chassis (Negative).
7. If the voltage differs from the battery voltage, the wiring harness
is faulty.
2) Glow Relay Test
1. Remove the glow relay.
2. Apply battery voltage across terminals 1 and 2, and check for
continuity across terminals 3 and 4.
3. If continuity is not established across terminal 3 and 4, replace
the glow relay.

I provided all the information on how the glow plug circuit works from the WSM and how to test everything in the other forum. Please read and follow the information in Post #3. I'm certain if you use this info, you'll find the root cause to your problem.


The dash indicator light is not proof power is supplied to the glow plugs. This is only an indication the ECU is commanding the low side of the relay.

 

[bferris01]

Ok, thanks everyone. Sorry but I am not great with a meter very basic only, so I will give it another shot. I do appreciate all the suggestions and help.

 

[bferris01]

Hello all,

So after following post #3 here is what I found.

Under glow plug lead terminal voltage:

I took the wire lead off (only wire- that went to the 1st glow plug and also a bar that connected the other plugs together) and got no reading with the switch off, then turned to ON (glow plug setting) and still got no reading.

Under glow plug Continuity:

I took the red lead from the meter to the top of the glow plug and the black to the chassis and 0.8 resistance.

Under glow rely:

The voltage was the same

I tested the relays (all 3--original OEM, replacement OEM with bigger terminals, and Autozone) and they tested and clicked as they should.


Soooooo.......that would lead me to think power is not getting sent to the main lead wire to the glow plugs themselves? Correct? Meaning- main ignition switch??? How to do I test it? I have checked the back and all connections are tight.

Hope I did you all proud...Thanks again.

 

[The Fred]

Do you Skype?

 

[bferris01]

I can facebook video from my phone or facetime I have iphone?

 

[bferris01]

Also I did poke around the ignition switch and think it is working correct. On the back of it the center spot has 12volt all the time, the spot on the top has none ever ( this is the off position), in the on/glow plug position the terminal on the back has 12 volt as well. So I think that means the switch is working right??

 

[moship]

Did you check the main 50 amp feed to the relay? This is the slow burn fuse and I believe is located near the battery.

 

[bferris01]

Moship - Yes Sir

 

[bferris01]

I checked again and the fuse at my battery is 80Am and good.

At the relay plug I have a red/black wire going into that has 12 volt all the time and a black/red wire leaving the plug and going to the glow plugs.

( When I jump these 2 with a piece of wire and cycle the glow plugs it starts like the day I bought it.


Also I tested the temp sensor:

Unplugged the sensor plug and got good continuity and then with the key in the on position I got 4.8 volts in the plug

Tested the sensor it self and no change on the meter/no continuity.

 

[The Fred]

Your problem is the primary circuit that trips the relay.

Be careful putting voltage where it doesn't belong as the instrument cluster is the controller for the glow plug relay, it grounds the control circuit of the relay allowing it to close.

Take a 12 volt light bulb like a 194 side marker bulb and stick one side in one of the small relay connectors and the other side in the other small relay connector terminal WITH THE RELAY REMOVED. Turn the key on like you are going to let the glow plugs cycle. The bulb should come on just like the glow plug light on the dash.

The workshop manual has all the info you require.

Regards, Fred

 

[arto98607]

Have you measured the resistance in each glow plug?

 

[Fallon]

Have you measured the resistance in each glow plug?

That's not particularly relevant. If he bypasses the relay everything works fine. Therefore the problem isnt with the glowplugs.