Block Heater buzz...

[CSM]

WWwwwwooorrrrrRRRRRRRrrrrrrrrrrzzzzzZZZZZZZZZZZzzzzzzzzzzzz!

So, last winter, I got this weird buzz from my block heater, and a very high current draw to the heater.  Popped a CB in the house.  And, like any true American would do, I reset the breaker and plugged that puppy back in!  I haven't used it since though.  

I Ohmed the plug, and couldn't find any leaks and summer was coming so I didn't worry about it.  

I was thinking of replacing the thing soon.  Has anybody had this issue?  

[Me78569]

did you pull the plug wiring out of the grill and look for any shorts or rubbing through the shielding?

[CSM]

Nope.  Thats a good thought.  I should do that.

[Royal Squire]

I had an open in the cord on my 12 valve at one time. Went to napa and they had an identical cord. Good as new!

[TFaoro]

1 hour ago, CSM said:

WWwwwwooorrrrrRRRRRRRrrrrrrrrrrzzzzzZZZZZZZZZZZzzzzzzzzzzzz!

So, last winter, I got this weird buzz from my block heater, and a very high current draw to the heater.  Popped a CB in the house.  And, like any true American would do, I reset the breaker and plugged that puppy back in!  I haven't used it since though.  

I Ohmed the plug, and couldn't find any leaks and summer was coming so I didn't worry about it.  

I was thinking of replacing the thing soon.  Has anybody had this issue?  

Okay first you just made my night!!  

Second... I've never seen a block heater itself go bad (I'm sure they do just no personal experience) but I've seen a lot of cords rubbed to the wires

[Mopar1973Man]

I now the block heater cord on my 2002 Dodge is shot and open current. As for my 96 Dodge the element in the block is open and no functional.

[Haggar]

CSM,

What values did you get when you ohmed it?  From leg to leg, you should read about 12 to 14.5 ohms (depends on the wattage of the heater) AND you should check for continuity of each leg to the ground. (looking for current leakage.)  There should be ZERO continuity to ground.

When it is quiet, I actually hear the water boiling near my block heater (a gurgling noise).  That would be normal.

You could have popped the breaker, due to the load.  a 1200w heater is pulling 10 amps.  Standard household circuits are broken on 15 amps.  high inrush can fool house breakers.  (ESPECIALLY if it is one of the newer arc flash or GFI types.) 

You may not have a problem at all.

 

HTH

Hag

[CSM]

7 hours ago, Haggar said:

CSM,

What values did you get when you ohmed it?  From leg to leg, you should read about 12 to 14.5 ohms (depends on the wattage of the heater) AND you should check for continuity of each leg to the ground. (looking for current leakage.)  There should be ZERO continuity to ground.

When it is quiet, I actually hear the water boiling near my block heater (a gurgling noise).  That would be normal.

You could have popped the breaker, due to the load.  a 1200w heater is pulling 10 amps.  Standard household circuits are broken on 15 amps.  high inrush can fool house breakers.  (ESPECIALLY if it is one of the newer arc flash or GFI types.) 

You may not have a problem at all.

 

HTH

Hag

 

i will check.  Thanks for the hard numbers! 

[Dieselfuture]

Just a thought, what if somehow ac voltage bleed to the truck and fry electronics? If 0.1ac volts from alternator is bad what will 110 vac do? If it's even possible. 

[Mopar1973Man]

That's why the the vehicle is grounded through the ground pin of the of the block heater cord. As long no positive side circuit came in contact with the hot side of the cord it would be pretty hard pressed to complete a 110 VAC circuit into the DC side.

Kind of like my solar system here on the house there is a fine line between 110 VAC of the house and the 24VDC of the batteries and the only thing shared in the ground.