Block Heater working but not working

[greg0145]

The block heater in my 5-year-old TC40D is drawing current (300-400 watts per hour) but is not effective this season. It has worked great in previous winters. My coolant level was also low, requiring nearly a gallon of antifreeze/water to fill the reservoir, and I was curious if the low water level may have damaged the block heater or made it not effective.

 

[Craig Clayton]

If the element is a block heater type and went dry it is a 50/50 whether you damaged it or not. Check with a Ohm meter between the black and white for you resistance value and then check between the black and or white to the ground pin and or the engine block. You should have infinity to the engine block and or ground pin.

E=IxR 120 V 2.5I 48 Ohm / Watts 120V x 2.5I = 300 W

If you want to test the current and you have NO test equipment you can plug and unplug the block heater in to clear type cord end in the dark and look for a tiny spark.

Craig Clayton

 

[TO_Bud]

Greg can you supply the group with a little more info on your problem. How did you determine the block heater was using the wattage you stated? Wattage is a unit of Power determined by volts X amps as CC has stated. If your wattage read is correct it sounds like the resistance of the block heater is somewhere near 40ohms, which is a tad high, but is doesn't sound like the heater has been ruined by low coolant. Is the glow plug circuit working correctly, and is the engine turning over quickly enough (good battery) to facilitate a successful start?

 

[RickB]

Greg can you supply the group with a little more info on your problem. How did you determine the block heater was using the wattage you stated? Wattage is a unit of Power determined by volts X amps as CC has stated. If your wattage read is correct it sounds like the resistance of the block heater is somewhere near 40ohms, which is a tad high, but is doesn't sound like the heater has been ruined by low coolant. Is the glow plug circuit working correctly, and is the engine turning over quickly enough (good battery) to facilitate a successful start?

It is supposed to be a 600 watt element.

 

[greg0145]

First a small correction, the tractor is a 2002 TC40D.

To determine the wattage I have a device called Kill A Watt EZ I purchased on Amazon. You can plug in a device, let it run for a number of hours, enter in your electricity cost per kilowatt, and it will display how much electricity the device used and how much it costs to run that device per hour, per day and per year. The meter indicated that the block heater consumed 8.7KW over a 21 hour period or about 414 watts per hour. I spot checked just now and it indicated 420 watts and 3.4 amps. When I plug in the block heater I can faintly hear it sizzle and this is normal from previous years. I measured the resistance at the three pins of the heater. They are not labeled. The resistance between the outer pins is 34 ohms. The resistance between the outer pins and the center pin or the block is infinity or open.

The glow plug circuit is working normal, the battery is new and indicated just over 12 volts (Red Optima with 800 CCA) The engine is not turning over quickly, that is the problem. It has been so cold, sub zero, that the engine will need to be heated in order for the engine to turn over quickly enough to start. In the past that only required the block heater to be plugged in for a few hours.

Just now I touched the heater itself and it felt warm but not hot after being connected for 10 minutes. I have never touched it before so an not sure if this is normal.

 

[RickB]

First a small correction, the tractor is a 2002 TC40D.

To determine the wattage I have a device called Kill A Watt EZ I purchased on Amazon. You can plug in a device, let it run for a number of hours, enter in your electricity cost per kilowatt, and it will display how much electricity the device used and how much it costs to run that device per hour, per day and per year. The meter indicated that the block heater consumed 8.7KW over a 21 hour period or about 414 watts per hour. I spot checked just now and it indicated 420 watts and 3.4 amps. When I plug in the block heater I can faintly hear it sizzle and this is normal from previous years. I measured the resistance at the three pins of the heater. They are not labeled. The resistance between the outer pins is 34 ohms. The resistance between the outer pins and the center pin or the block is infinity or open.

The glow plug circuit is working normal, the battery is new and indicated just over 12 volts (Red Optima with 800 CCA) The engine is not turning over quickly, that is the problem. It has been so cold, sub zero, that the engine will need to be heated in order for the engine to turn over quickly enough to start. In the past that only required the block heater to be plugged in for a few hours.

Just now I touched the heater itself and it felt warm but not hot after being connected for 10 minutes. I have never touched it before so an not sure if this is normal.

After 10 minutes, you should not be able to keep a fingertip on the heater. They should get REAL hot, to the point of almost raising a blister. Time to R&R the element.

 

[Craig Clayton]

It sounds like the block heater is producing 400 watts. I do not know how big it should ie 300,400, or 600watts. How cold is it and how many HP is the engine Ie the size of the block?
Craig Clayton

 

[greg0145]

I'm not sure about the size of the heater. It worked before, but does not seem to be transferring enough heat now.

The temperature has been 15-20 most of the day today but it was minus 5 during the night. The engine is a 40 HP diesel.
(If I put a 75 or 100 watt trouble light under the hood overnight and cover it with a blanket, the tractor will start if the temperature is in the teens)

If parts are involved, does anyone have a favorite online dealer?

 

[Craig Clayton]

RickB is sure it is 600 watts. And according to the math you are only producing 420 watts. Here are the options
Clean the pins that I believe are the terminals on the block heater because if they have some corrision that is resistance and that will reduce your current ie WATTS.
The cord that pushes on the pins could have a dirty oxided connection ie reduced watts.
As suggested by RickB tear it out R+R.
Put on a lower rad hose heater but I do not know about 600 watts rating.
The 400 watts you PRODUCING SHOULD WARM IT UP it just will be slower to heat.
Wait until it is warmer and R+R.

I am all out of race track, the choice is now yours.
Craig Clayton

 

[TO_Bud]

RickB is the authority on all things NH so I would go with his recommendation. 600W on the heater works out to 24 ohm resistance on the element. Your readings indicate about double that at 40+ohms so the element is suspect. I'm still worried about the starting circuit though, I have a TC40D and it has been single digit temps here the last week or so. I don't have my heater plugged in and I still start up with no problem. I do cycle the glow plugs 3 times before turning it over but it fires right up. There is some rpm hunting for a few seconds but it smooths out quickly. So if you are turning over slow I would check for poor connections both positive and neg at the starter and battery or have the starter tested for high amperage draw. Lastly and more simply what weight oil are you running? If it is 15w-40 then you will need a fully functioning block heater to warm it even if all other items mentioned here are in good order.