L3240 won't start when cold... Help!

[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 (with the newer bigger terminals) 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.

I did search and saw another similar post but different model ad didn't want to hijack that post, hope this is ok.

 

[JerryMT]

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 (with the newer bigger terminals) 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.

I did search and saw another similar post but different model ad didn't want to hijack that post, hope this is ok.

I don't have any specific knowledge of your Kubota model so my suggestions are of a general nature.

Are all the battery terminal "bright an tight" including the chasis ground connection? Do you have power to the glow plugs? "White smoke" is unburned fuel. Since it started when you jumped the relay and you said you replaced the relay, assuming the new one is good, implies your problem may be upstream of the relay. I would think that is between the key switch and the relay.
Sorry I can't be of more help. Someone will show up with more experience on your model and maybe able to provide more suggestions. In the mean time check the battery connections including the ground.

 

[200mph]

I'd check the supply voltage to the glow plugs to ensure it is near battery voltage. If it is not, work backward through the wiring until you find the source of the voltage drop.

Also be a bit careful with the relay selection. Since your relay is operated by the ECU, I'd make certain the replacement has the appropriate diode, so it doesn't send a voltage spike back through the ECU.

I'd also check the 50 amp fuse near battery to make certain it is good and there is good continuity across the terminals.

Below is info found in the WSM (Grand L40-3) in the event helps in any way. Sorry I can't include pictures/diagrams. For that you'll need to invest in the manual.


(4) Glow Control
The electronic meter incorporates the glow control which was external single parts so for, and controls it with CPU.
When the main switch is turned "ON", the temperature of the coolant is detected with the coolant temperature
sensor, and the time to supply current to the glow plug and the glow indicator lamp is controlled by CPU according to
the detected temperature. And the supply current to the glow plug is stopped automatically when the preheating time
is completed, and monitor lamp on the electronic meter panel is turned off. (Refer to "STARTING SYSTEM".)

Glow Plug Resistance Approx. 0.9 ***937;

20 pin connector
Pin 11 Black/Red Glow relay

Glow Plug Lead Terminal Voltage
1. Disconnect the wiring lead (1) from the glow plug (2) after
turning the main switch off.
2. Turn the main switch key to the "ON" position, and measure the
voltage between the lead terminal and the chassis.
3. Turn the main switch key to the "START" position, and
measure the voltage between the lead terminal and the chassis.
4. If the voltage at either position differs from the battery voltage,
the wiring harness or main switch is faulty.

Voltage (Lead terminal ***8211;Chassis
Main switch key at "ON" Approx. battery voltage
Main switch key at "START" Approx. battery voltage

Glow Plug Continuity
1. Disconnect the lead from the glow plugs.
2. Measure the resistance between the glow plug terminal and the
chassis.
3. If 0 ohm is indicated, the screw at the tip of the glow plug and
the housing are short-circuited.
4. If the factory specification is not indicated, the glow plug is
faulty.
Glow plug resistance Approx. 0.9 ***937;


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.

Good luck and please post back what you find.

 

[bferris01]

Thanks guys,

So I got the meter out ( I am a novice with it) and check the relay. With the key off I get 12V to one leg, with the key in glow plug position I get 12V on 2 legs.

Both replays are OEM, I swapped them and put the meter on both relay plugs and get the same results.

I get the normal click and light stays on and them goes off.

I checked the main 80amp? fuse at the battery and it is good.

Does the engine temp sensor play any role in this process? Or is that just how it reads on the dash?

Does anyone know where the controller is located, I can't find it listed in any parts diagrams.

 

[D2Cat]

Don't know what your air temperatures are, but be sure you have fuel treated for the conditions your operating in.

 

[thepumpguysc]

Post # 3.. {4} glowplug.. 2nd sentence.. the coolant temp sensor should be by the thermostat neck.?? {Just guessing here}

 

[200mph]

Thanks guys,
Does the engine temp sensor play any role in this process? Or is that just how it reads on the dash?

I tried posting all the relevant information from the WSM in Post #3. There's a great deal of info in the post and perhaps it is worth a 2nd review...

(4) Glow Control
The electronic meter incorporates the glow control which was external single parts so for, and controls it with CPU.
When the main switch is turned "ON", the temperature of the coolant is detected with the coolant temperature
sensor, and the time to supply current to the glow plug and the glow indicator lamp is controlled by CPU according to
the detected temperature. And the supply current to the glow plug is stopped automatically when the preheating time
is completed, and monitor lamp on the electronic meter panel is turned off.


If the coolant temperature sensor sends the incorrect resistance value given the temperature, the ECU (computer) will calculate the wrong glow plug on-time. Too short of a time could make it difficult to start.

 

[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.

 

[200mph]

In the event you want to verify your coolant sensor.

-20C (-4F) 18.89 ohms
40C (104F) 1.136 ohms
100C (212F) 0.1553 ohms


Calculated the exponential function based on the above data and come up with:


y = 7.3773e(-0.04C) When measuring in degrees C

or

y = 15.014e(-0.022F)

where C or F is the coolant temp in degrees C or F and y would be the resistance measured in ohms.

 

[200mph]

Main power to the glow plugs is not through the switch. It couldn't handle the current.

Again, the power to the glow plugs is protected by a 50 amp slow burn fuse from the battery. Check to make certain fuse is good and there is battery voltage at the fuse and move towards the glow plug form there. I think I posted the wire color in the earlier post.

The switch and ECU only controls the small amount of current to energize the relay coil and is a much smaller diameter wire.

 

[bferris01]

WOW 200mph....making my head hurt!

So again I am not a meter wiz but I unhooked the sensor and there are 2 small prongs, I put the meter on resistance and the meter never changed, if I did it correctly.

Could I jump the plug side just to see if it would start or would that be a bad idea?

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??

 

[200mph]

WOW 200mph....making my head hurt!

So again I am not a meter wiz but I unhooked the sensor and there are 2 small prongs, I put the meter on resistance and the meter never changed, if I did it correctly.

Could I jump the plug side just to see if it would start or would that be a bad idea?

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??

To test the temp sensor you'll need to adjust your meter to read ohms. The symbol looks like an upside-down horseshoe.

You really need to test the main power for the glow plug. It is not in the key switch. It is a separate larger diameter wire that comes from the battery to a 50 amp fuse. The wire color is labeled B/R in the wiring diagram, so I'm guessing this is Black with a red tracer. Please measure this voltage and verify you get battery voltage and report back.

 

[bferris01]

200mph.....

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.

Hope I answered you questions?

 

[bferris01]

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.

Hope that helps.

 

[200mph]

If you look at the fuse contraption at the battery. It is 80 amps on top and below are 4 fuses that don't look like fuses. They are marked with different amp ratings. The black with red tracer is the power for the glow plug. This wire goes to the relay connector and you should see the larger black with red tracer wire where it enters the relay connector.

As a side note. The picture in the WSM identifies the glow plug on the left hand side, but on my tractor it is the right most relay. I just took my front end off and the dash panel to verify what I'm telling you. (My tractor L4740-3 cab)


"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."

By your description the relay might be bad. Just because it clicks doesn't make it good. The contacts inside can be badly pitted and unable to carry the necessary current. It could also be that the ON time is much longer than calculated by the controller.

Can you disconnect the GP wire at the glow plug buss bar? Disconnect and see if battery voltage is present at this wire when GP circuit is energized (GP light on in dash). I suspect my glow plugs also as this tractor has a harder time starting in the winter compared to the L3130, but with the AC unit and other components I can't access my GP buss bar supply wire or even see it without major disassembly.

Send me a private message with a phone # and I'll call.

 

[200mph]

A few pictures that may help support your effort.

Relay position: The WSM shows the relay on the left hand side. Mine is on the right.

To test for power at the Glow Plug itself the wire must be removed from the Buss Bar first. On cab tractors this is difficult because of the AC compressor and other bracketry. There is connector located above the oil filter that can be disconnected and tested for battery voltage when the GP is commanded on. Battery power at this point would indicate relay is working. It is still possible the connection to the GP Buss Bar is faulty, but testing at this connector rules everything else out when dealing with cab tractors.

The slow burn fuses are attached to the positive battery connector.

Hope this helps the OP or anyone else troubleshooting this circuit.

 

[200mph]

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.

When testing the sensor the connector should be removed from it and the meter set to measure resistance or ohms. On the meter the symbol may look like an upside down horse shoe. Connect the meter leads to each terminal and read the value. If you get an infinite reading the sensor is no good and your dash panel will likely not show the engine coolant temperature changing.

 

[bferris01]

Sorry I had to run yesterday, my son had 4H things we had to do.

200mph- Thanks for the pictures I did miss those fuses until I took off the grill but they are all good (there are 2 50amp and 2 80amp)

I also checked resistance on the temp sensor with it off and meter didn't change, but I jumped the relay and started the tractor and got the temp up to operating temps on the instrument panel and then unplugged it and check resistance on the sensor again and it was something like .478

I don't have that connecter plug coming from my glow plugs and bus bar, it goes straight into the large main bundle of wires.

I did test each glow plug for resistance and got .8

So I have 3 relays now the OEM upgraded large terminal one I just bought and is now in the tractor, the OEM orginal one that came with it, and a cheap auto zone one I brought. I don't think they all could be bad?

Also I checked continuity from the ground side of the relay plug to the frame and it is good as well ( I was thinking maybe a bad ground)

Thoughts?

 

[bferris01]

Sorry I missed your last question:

When I disconnect the wire that feeds the bus bar/1st glow plug, I get no voltage at all when the key is turned to on/glow plug position.