Block Heater check up, advice on testing it with a meter???

[Brad S.]

So of course after I've got the engine almost ready to fire, I think about checking the block heater...And since our weather is staying cold.
(Maybe I noticed it laying underneath hooking up exhaust)
Anyway, curious if a person can put a volt meter on the cord end and get a reading...?? And what those readings could mean???

 

[3Kp]

First check the cord for continuity. Unplug both ends and test the wires with a ohms meter or continuity tester. There are 3 separate wires- center one is ground and 2 outer ones are live. Look for damage such as opens and shorts, and replace if necessary.

If the wire is OK connect ohmmeter to the 2 terminals of the element (block heater)There should be a very low reading almost zero. If the ohmmeter shows the heating element to be open (infinite ohms) replace block heater.

hopefully that helps.

 

[Brad S.]

Yep, it does help, I'm pretty sure it works, but I'm wondering if some reading/resistance can tell how well its working...
The heater worked last year, but just to make sure.
Of course when I get close to starting it, I'll plug it in and listen for the sizzle..

 

[BDCarrillo]

Plug it into a kill-a-watt or use to see the draw. A clamp type meter may work too. They are 1000w elements, right? Some math will tell you the total draw.

 

[3Kp]

With my plumbing background when I test water heater element they usually read 12.5 ohms(that's a good one) but they are 4500 watt elements.

 

[Robt.Webster]

With my plumbing background when I test water heater element they usually read 12.5 ohms(that's a good one) but they are 4500 watt elements.

I think that you will find the resistance of the block heater to be ~16 ohms. If you find an open circuit at the plug, test directly at heater itself. If it's good there, work your way along the cable by piercing the insulation starting at the plug until you get a normal reading. Just a note, if you have left the cord hanging out of the grill, you will most likely find the break close to there as the factory cable is not too robust, and flapping around in the breeze tends to break the wire internally. If it's there, you can install a new plug downstream of the break.

Good luck!

 

[cpdenton]

Checked the one I have in my toolbox. Brand new in the box. It tested to 32 ohms.

 

[Robt.Webster]

Checked the one I have in my toolbox. Brand new in the box. It tested to 32 ohms.

32 ohms will only give you 450 watts...for 1000 watts the resistance should be around 15 ohms give or take

 

[cpdenton]

That's what I thought. This one was small, but has a nice cord on it. I bought it for the cord really!