Block Heater

[HJanin]

Help! I am having troubles with blowing my GFI (Ground Fault Interupter) on my outside 120 volt plug when I plug in my '99 Dodge 3500 Quad at night. It just started happening about 1-1/2 week ago and was fine before then. I took it into the dealer and he told me that it's doing what it's supposed to. So, I changed the GFI and it blows as soon as I plug the truck in!

Any suggestions? I live at 9,400 ft. elevation in Colorado and we just got more snow last night!

Fortunately, I was able to plug the truck into another circuit without a GFI and the heater seems to be working.

 

[TomGolden]

Well, I haven't had that problem on my 2001 ETH, but I plug mine into a 15A breaker. I don't know how much current the block heater draws, or if the outside air temp makes any difference to how much current it draws to keep the engine warm overnight.



If the plug you have used is only a 10A circuit, maybe try a 15 or 20A circuit if you have an open one??



Tom

 

[HJanin]

Thanks for the quick reply. I replaced the old 15 Amp with a new 20 Amp GFI! I wish I knew how much current it's supposed to be drawing but then again, I don't have an amp meter. It's just weird that it Just started doing it.

 

[ftb87]

How many items do you have pluged into the whole circuit? Also, when you changed out the old curcuit, it could have been bad.





Frank

 

[zimman20]

You can also pick up a circuit tester at any Home Depot or Lowe's, they're (usually) yellow with the prongs on one end and three lenses on the other. You plug it into the outlet and it will give you a color code on the three lenses indicating either circuit OK, missing ground, missing neutral, etc. to let you know if/what the

problem is. You may have a bad circuit, you'd be surprised what will work with a missing neutral or ground, that doesn't make them safe.



I would never discount the fact that a GFCI is tripping, take heed! It may be doing what it's supposed to be doing.



Or you or your significant other may have recently plugged some- thing into the circuit that wasn't there before, causing the overload...



If it was working before I wouldn't just upgrade the GFCI to a higher rated one, you could overload the circuit and cause a fire.



FWIW I believe I read on here somewhere that the block heater only draws in the neighborhood of 500-600w (someone correct me if I'm wrong) which is not much.





zman

 

[zimman20]

One more thing.....

To find how many amps a device is drawing when Watts is known, divide the watts by the voltage (600/120= 5A)..... zman

 

[TURBOs4LIFE]

GFI

If the GFI is tripping its due to a problem with the ground getting live current in it through the block heater if its tripping when you plug it in and not a overdraw of amps. I believe I have seen the block heater uses 750 watts.

 

[HJanin]

That's my gut reaction, as well. However, if that Was the case, wouldn't I also be blowing the other circuit breaker? And (of course) why couldn't the 5-star dealer find anything wrong? The only thing I remember happening around this time was that my dog located a 'wild' cat under the truck(we live in the country). But I couldn't see anything physically wrong with where the cord connects to the block.

 

[Shooter]

Frijole had the same problem this winter. It ohmed ok but kept tripping GFI. We pulled it for inspection ( I have worked w/ block heaters for a lifetime ) and it had cavitated the copper jacket ( cavitation occurs when the coolant boils on the element surface and the bubbles collapse ) and coolant had infiltrated the calrod unit. A trip to Cummins for a new one solved the problem. It will still heat if you put it on a non-GFI circuit but you will get BITTEN if you are grounded and touch the truck. Good luck with the 5 screw stealer.

 

[Extreme1]

Odds are their test consisted of plugging it in to a non-GFI circuit, listening for it to boil (or feeling for heat) and saying "Yup, it's fixed. "

 

[Sixpack]

Was it raining when you were having the problem? If so keep the plug out of the rain. Also it could be a bad spot in your cord that is getting wet. Hope this helps. . Phil

 

[HJanin]

Well, thanks for all of the replies. To answer the last one, it Very Rarely rans here, at 9,400 ft. What we get is snow and usually lots of it! I believe the reply about a corroded element, partially because I have to plug the truck in about 6 months out of the year. Our last snowfall last year was June 13th!

By any chance, do you have a part number for the element?

Thanks

Howard