Block Heater
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Senior User
Joined: Jan 2012
Posts: 359
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From: Harrisonburg, VA
Block Heater
How can i test if my block heater is working? Idk what it looks like or where its at. I really do not think its working because i never feel any heat coming off any part of the block after she sits for 24hours even with it plugged up.
Also about how much would a new block heater run me?
Also about how much would a new block heater run me?
Senior User
Joined: Sep 2008
Posts: 318
Likes: 1
From: Portage Des Sioux, Mo
Block heater is in 1 of the freeze plug holes on passenger side of block, toward rear. I have not checked mine yet (need to also), but try using a ohm meter between the 2 blade leads onthe plug. Not sure what it should read but it should not be open or a dead short most likley about atleast 10 Ohm but not more than 200. Dont know the other answers.
Fleet Owner
Joined: Jul 2006
Posts: 20,377
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From: Mi'kma'ki
its Dave Sponaugle memory lane time!
(man,he's greatly missed.
)
...........................
(man,he's greatly missed.
)Block heater come in a variety of wattages.
Because of that, resistance can vary.
26.4 ohms = 500 watts
13.2 ohm's = 1000 watts
8.8 ohm's = 1500 watts
That is three examples, I have seen 600, 750, 900, 1200 and several other wattages over the years on top of the ones I listed above.
Because of that, resistance can vary.
26.4 ohms = 500 watts
13.2 ohm's = 1000 watts
8.8 ohm's = 1500 watts
That is three examples, I have seen 600, 750, 900, 1200 and several other wattages over the years on top of the ones I listed above.
Unplug the cord from the block heater and bench test it. I've found many of these cords break right at the male end you connect to the extension cord. If it has continuity check the freeze plug for continuity. Sometimes the cord is not making good contact with the freeze plug prongs. If the freeze plug shows 0 continuity replace it. I use a 600 watt up here. It warms up my old 1984 6.9 or my 1991 7.3 enough in 30-45 minutes to start at -20.
That works out to 850 watts.
How long is your extension cord?
You may need a larger AWG cord.
3 volts of drop to 118 volts is not bad, but 110 volts is to low.
You should supply a minimum of 115 volts to the heater.
In the electrical business,
Almost all devices are designed for a minimum of 115 volts.
The supply voltage at the electric panel is usually aroung 120 volts.
So when you wire something, you take the length of the circuit and the amp load to figure out what size wire you need to to keep the voltage drop under 5 volts from the panel to the device.
Any device running on low voltage will fail before one that has the proper voltage supplied to it.
You may also notice the cord gets warm, which is putting heat out where it is wasted instead of in your engine where you want it.
How long is your extension cord?
You may need a larger AWG cord.
3 volts of drop to 118 volts is not bad, but 110 volts is to low.
You should supply a minimum of 115 volts to the heater.
In the electrical business,
Almost all devices are designed for a minimum of 115 volts.
The supply voltage at the electric panel is usually aroung 120 volts.
So when you wire something, you take the length of the circuit and the amp load to figure out what size wire you need to to keep the voltage drop under 5 volts from the panel to the device.
Any device running on low voltage will fail before one that has the proper voltage supplied to it.
You may also notice the cord gets warm, which is putting heat out where it is wasted instead of in your engine where you want it.
Also if the temp is extremely cold, just heat the glow plugs 10 seconds, wait 20 seconds and heat them 10 seconds again. I have started my engine without the block heater at 15 below doing this. if the engine starts to stumble after starting at very cold temps, hit the glow plugs for 4 or 5 seconds with the engine running to keep the cylinder temp up enough for the fuel to burn since it is sucking in very cold air and the block is not warm yet.
Lead Driver
Joined: Mar 2006
Posts: 5,111
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From: western SD
X2 I learned a lot from Dave, I whish he would chime in again!
Elder User
Joined: May 2005
Posts: 567
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Measuring power consumption of a block heater
It's hard to measure ohms in the range 10 ohms or less, due to the built-in inaccuracy of multimeters.
The way I recently assessed my in-block heater was to use a consumer-grade watt meter, tradename "Kill A Watt"
I plugged the watt meter into my extension cord, then plugged my block heater into the outlet on the front of the meter. I read 115 VAC on the watt meter's screen, which matches Dave's specification of the minimum AC voltage necessary to run common AC appliances.
It was a cold day. I put the watt meter under the hood, where no rain or snow could fall on it - it is not designed to be left out in the weather. I let the block heater warm my engine for 3:16 hours. Then I pushed the various buttons on the watt meter for a readout of what had happened. The block heater had consumed 2.74 kilowatt-hours (kwh) of power in that time. I pay 10 cents/kwh, so my block heater cost me 27.4 cents to run for 3 hours & 16 minutes.
2.74 kwh divided by 3 hours, 16 minutes gives 839 watts of power drawn by the block heater in my engine.
I could feel a bit of heat in the top hose to the radiator. My engine started easily.
The watt meter has many other uses around the house. I once left it on a chest freezer in my basement for a month & was pleasantly surprised at how little it costs me to run the freezer.
The way I recently assessed my in-block heater was to use a consumer-grade watt meter, tradename "Kill A Watt"
I plugged the watt meter into my extension cord, then plugged my block heater into the outlet on the front of the meter. I read 115 VAC on the watt meter's screen, which matches Dave's specification of the minimum AC voltage necessary to run common AC appliances.
It was a cold day. I put the watt meter under the hood, where no rain or snow could fall on it - it is not designed to be left out in the weather. I let the block heater warm my engine for 3:16 hours. Then I pushed the various buttons on the watt meter for a readout of what had happened. The block heater had consumed 2.74 kilowatt-hours (kwh) of power in that time. I pay 10 cents/kwh, so my block heater cost me 27.4 cents to run for 3 hours & 16 minutes.
2.74 kwh divided by 3 hours, 16 minutes gives 839 watts of power drawn by the block heater in my engine.
I could feel a bit of heat in the top hose to the radiator. My engine started easily.
The watt meter has many other uses around the house. I once left it on a chest freezer in my basement for a month & was pleasantly surprised at how little it costs me to run the freezer.
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Freshman User
Joined: Jan 2012
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when i plug my truck in ( live in iowa gets a little cold) and it is 0 outside in the morning i can pop the hood lay my hand on the head passenger side around the exhaust manifold and it is not cold maybe 50 60 degrees F
have fun changing it too its behind the starter so it is easier to remove the starter plus have to drain radiator unless you like getting wet and waisting antifreeze
have fun changing it too its behind the starter so it is easier to remove the starter plus have to drain radiator unless you like getting wet and waisting antifreeze
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the aliens from planet Navistarina in the dieselena galaxy abducted him because they needed him to educate their doctors on how to properly keep the citizens running in tip top condition. 
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