Lmm won't start?

plowboy_lbz

Farmer
Aug 6, 2013
431
0
0
Ok well I guess what I was trying to point out is the heater doesn't make the coolant hot enough for the heater to work. And doesn't warm the coolant enough that the glow plug cycle would be shortened. In the book it only says to plug it in if the temp is going to be below -20 F and leave it plugged in for atleast 8 hrs. So 30 - 60 min of being plugged in isn't going to make a difference. My trucked starts just as good at -15 plugged in or not.
 

Ne-max

I like turtles
Nov 15, 2011
3,361
64
48
Lincoln, Ne
Ok well I guess what I was trying to point out is the heater doesn't make the coolant hot enough for the heater to work. And doesn't warm the coolant enough that the glow plug cycle would be shortened. In the book it only says to plug it in if the temp is going to be below -20 F and leave it plugged in for atleast 8 hrs. So 30 - 60 min of being plugged in isn't going to make a difference. My trucked starts just as good at -15 plugged in or not.

Just stop typing. Please
 

Harbin_22

Active member
Dec 4, 2010
3,858
7
38
Southern Indiana
My block heater will have my coolant up to 130-140° in 3 or 4 hours. My glow plug light won't even come on if it has been plugged in. If you block heater is working correctly you should notice a huge difference in the sound of the engine on a cold start. Mine sounds like it has been running all day after being plugged in. As far as the temp of when to plug them in, it doesn't matter. You can plug it in whenever you want.
 

plowboy_lbz

Farmer
Aug 6, 2013
431
0
0
My block heater will have my coolant up to 130-140° in 3 or 4 hours. My glow plug light won't even come on if it has been plugged in. If you block heater is working correctly you should notice a huge difference in the sound of the engine on a cold start. Mine sounds like it has been running all day after being plugged in. As far as the temp of when to plug them in, it doesn't matter. You can plug it in whenever you want.

Evidently My heater wasn't working right. Only used it a couple times and couldn't tell a difference so I quit. I will have to try my other truck.
 

MACKIN

Smell My Finger...
Aug 14, 2006
3,948
1
0
Connecticut
I know when you plug these trucks in the heat comes a whole lot sooner then NOT plugged in. Nonetheless it definitely heats the coolant.

IMO the OP has a battery issue. If they are the OEM batteries they are on their way out they are a 3 year battery at best! Cold cranking amps is where they show their weakness.

If they are replacement you didn't buy a good diesel CCA sufficient battery. I had a friend who did that . Brand new Auto Zone battery would NOT start in the cold or where sluggish. Whether you are gelled or not plugged in the engine should spin over and not kill the batteries unless you've been trying to start for a great length of time but I don't see this as the case here.
 

DMAXchris

It’s only temporary!
Apr 28, 2009
2,273
2
38
44
Natrona Heights PA
Ok well I guess what I was trying to point out is the heater doesn't make the coolant hot enough for the heater to work. And doesn't warm the coolant enough that the glow plug cycle would be shortened. In the book it only says to plug it in if the temp is going to be below -20 F and leave it plugged in for atleast 8 hrs. So 30 - 60 min of being plugged in isn't going to make a difference. My trucked starts just as good at -15 plugged in or not.

When I plug my truck in the glowplug light never comes on and the heater blows warm air.
 

young582

New member
Nov 28, 2013
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We'll I left it plugged in all night after cranking it last night I had weak batteries I threw the charger on after it being plugged in all night and it fired right up
 

DMAXchris

It’s only temporary!
Apr 28, 2009
2,273
2
38
44
Natrona Heights PA
That's what I've been hearing. I guess my block heater wasn't ever working.

I think you can test the plug for resistance to see if it's working. I remember reading a thread a few years ago that said the plug shorts out or something along those lines. Don't quote me on it though. lol.
 

young582

New member
Nov 28, 2013
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I think you can test the plug for resistance to see if it's working. I remember reading a thread a few years ago that said the plug shorts out or something along those lines. Don't quote me on it though. lol.


Ok. The light comes on with all the dash lights and goes out with them there for I don't beleive they are working properly I don't beleive I have any codes when I first purchased the truck I had a glow plug module code I erased it and it never came back on
 

MACKIN

Smell My Finger...
Aug 14, 2006
3,948
1
0
Connecticut
My batteries are new they were weak from trying to get it started last night I tried probably 10 times befor the crank got slow

Ok then at that temp you'll have to keep it plugged in over nite then ,then it should fire right up with no assist.
 

03Tommy

New member
Jun 2, 2008
83
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Weston, Mo
I think you can test the plug for resistance to see if it's working. I remember reading a thread a few years ago that said the plug shorts out or something along those lines. Don't quote me on it though. lol.

Correct, you should get 11-15 ohm out of the plug. I replaced a cord in my Duramax before I sold it and just had to put a block heater in my powerstroke. It is very rare for a block heater to go bad. Ask any parts store or dealer. They usually wont even have a block heater in stock but will have a few cords.
 

t2timmy

2015 LML Denali
Jun 28, 2013
92
1
8
CT
Here's a dumb question (because I'm a learner too)...... when you guys replace your battery... because they start going bad like this..., do you always replace both at the same time? This is my first Diesel and I'm assuming the battery's in it are O.G. Going to be cringing the day that purchase has to happen?
 

Ne-max

I like turtles
Nov 15, 2011
3,361
64
48
Lincoln, Ne
Here's a dumb question (because I'm a learner too)...... when you guys replace your battery... because they start going bad like this..., do you always replace both at the same time? This is my first Diesel and I'm assuming the battery's in it are O.G. Going to be cringing the day that purchase has to happen?

Correct. Always do 2. If not the used battery will take out the new battery quick.