Block heater

[dogrider]

How can you tell it your block heaters working? I have read that alot of the time its the cord and not the element, but how can I test it. And if the heater is working would the block or where the element goes in to block be warm or hot. It is crazy cold for us in southeast New Mexico. I think it got up to 4 deg with wind chill of -21 today and in minus's tonight so didnt know if I got under truck and felt around if i could feel the warmth from the heater. Im hoping this is problem. Thanks Chris

[ekfinn]

Get ahold of an ammeter and plug 'er in. You can expect 5-6 amp minimum load on the line. Find one of those nifty induction-based clamp-around-the-wire testers. If the cord is bad, you're not going to have load on the circuit.

[str8razor]

I may be too late replying to this but I wanted to post something in case you haven't done anything with it yet. The ammeter is not a bad suggestion but, you can't clamp around both wires togeter (the whole cord) because the common wire will cancel out what the hot wire should read and you will get a reading of almost zero. You have to seperate the two wires and clamp around only the hot side. But, maybe there's another ammeter that can read ampherage while clamped around both wires that I'm unaware of and I've just learned something new.

Before you do the following, make sure you DO NOT have the block heater plugged up as you DO NOT need power to perform this test. What I would do is use a multi meter set to OHMS and touch one lead to one prong of the block heater plug and the other lead to the other prong. If you are unfamiliar with reading OHMS, before you take a reading on the heater plug just simply touch the two leads of your meter together and see what the meter tells you. By touching each lead together you are simulating a complete circuit with full continuity. If it's an analog meter, the needle should peg out. If it's a digital meter, the moment you touch the leads together, the screen should change and read all zeros or something like .0001 or .0002 depending on how many decimal places your meter has. If your meter doesn't change when you read across the prongs of the plug then you know you have a broken connection somewhere in the circuit. Without looking at my block heater plug, I'm not sure if the cord can be taken off the element and tested by it's self. I would think the plug is a molded part of the element but I may be wrong. By chance, if the cord can be disconnected from the element, you can then read OHMS from the prong to the end you disconnected from the element. You won't have any way of knowing which end of each wire is for which prong on the plug so you will want to touch one lead to one of the prongs then see if you get a reading on either of the two wires on the opposite end of the cord from the plug. Do this same thing with both prongs. If you are unable to get a reading from one prong to either of both ends of the wires, you have a bad cord.

Sorry for writing the book but, if you are unfamiliar with using a meter, I wanted to explain how to use it.

Hope this helps.

[dogrider]

Thanks 4 helping.........Chris

[str8razor]

When I got home, I OHMed my block heater which I know is working. You should get a reading of around 15 OHMS when reading continuity from one prong to the other. My multi meter showed 15.2 OHMS. I need to make a correction of the reading you will get when you touch the two leads togeter. Mine is digaital and it toggles between 0.3 & 0.4 when I touch the leads together.

[Gruss]

razor, nice write up.

[Mutley]

If meter challenged (like myself) you should probably know if it's working by plugging it in overnite and starting it the next morning. Assuming batteries and GPR are in good order it should spin and fire right away without any loping or other goofy sounds....and....your water temp guage should be off the bottom somewhat. In stock form these trucks ***** and moan when cold started without plugging in for sure from what I've seen and it's been a long cold winter up here.

[BIGCREW]

the plug usually goes bad right at the end of the plug,heres a way to check without a meter,cut the plug off and seperate the wires and skim around an inch of the coating off,now take your drop light and stick the wires in each side as if you were pluging it in,if you get sparks its working replace your plug,mine tested good with the meter but it was because I got lucky and it was making contact,the wires tend to break in strands and can also get very hot and cause other problems

[Mutley]

When I got my truck the plug end was cut off. I never stopped to think the block heater was bad so I wired up a new plug and it's worked fine but this winter it shorted again (I think due to corrosion and other nonsense inside the plug end). I've replaced it with a sealed heavy duty wire and plug and all is well once again. So yes, bottom line, bad things happen to the plug ends on those things and it sure doesn't hurt to replace it occasionally as required. Road salt is a beeeyotch.

[bohawg]

yep usually its the end of the plug,, i plugged mine in when i first got my truck and the end got really hot so becarefu and check it after a hour or so. So i just cut mine back and put a new end on it thta was like for 14 amps or 16 and its working good now..