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Help - Engine Block Heater failure/burned up!

Discussion in 'Gen 2 Prius Main Forum' started by Snagtooth, Feb 6, 2009.

  1. Snagtooth

    Snagtooth Junior Member

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    Hello all. I wasn't sure whether to post this here or in the mods section for the best response, so moderators feel free to move it if appropriate.

    2 weeks ago today I plugged my EBH in for the night and was in for the evening. The next morning (a Saturday) I went out to unplug for a trip out and was dismayed to find the plug disintegrated in my hand as I attempted to unplug from the extension cord. My EBH had burned up and the breaker tripped in the garage knocking out power in my garage!

    Some background information:

    I had the EBH installed professionally by a local customizing shop (my neighbor's business) as I could not get the car up high enough to do it myself with my normal ramps. So yeah while it was expensive, it saved me some time and effort as well as kept me out of the cold since we were already in winter. Seemed to work fine for several weeks. I bought a heavy duty timer specifically made for block heaters and had a heavy gauge extension cord - plus it was plugged into a ground fault outlet for safety. However, I had always wondered if something was not quite right as the temps were in the low 120's after unplugging. I never gave this too much thought though as visual inspection and touch inspection appeared to be ok as far as the installation goes and the block was always warm to the touch when checked (not scalding but warm). Plus, with the unusually cold weather - I was not sure what to expect temp-wise. Curiously the only part of the cord that was melted was the part right up by the plug (the flex portion). The shielded part snaking along the engine was fine all the way back to the block. Also the timer and cord were all fine as well. (I did have to cut the plug off the end to get it snaked back through the grill for removal.)

    So what the heck happened?! I naturally was worried that the install was not done properly and explained my concern to my neighbor when I took the car back in to have him remove it. I had even printed the detail install instructions from here with full size color pictures for them when they did the original install. He assures me that the install was fine and everything looked fine when they removed it. He also assured me they read and followed the guide I printed from here to the letter. His concern was for the quality of the block heater itself. He said he remembered thinking it looked a little suspect to him when they did the install (read...cheaply made, whatever). I know the guy fairly well and would hate to think he was conning me on their work, but wow I am at a loss to explain this.

    Anyone else have any ideas? As it stands I am out the cost of the heater, $115 for the install and another $37 for the removal. If he is telling me the truth, I'd like to request a refund for the EBH. I am not sure if replacing it is the right way to go or not as I am concerned about the potential for another frying and possible garage fire on the extreme side.

    Any insights are appreciated, especially of you folks who have installed dozens of these things. I hate to lose my winter mileage, but the risk / expense of a rinse and repeat is not exactly appealing at the moment.

    Thanks much.
     
  2. efusco

    efusco Moderator Emeritus
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    A common failure of the EBH cord occurs right at that reinforced area at the plug end due to repeated flexing at that point. Probably you had a short there that caused the wires to melt.

    I bet the EBH itself was/is fine and all you need to do is fix the cord.

    What I now have done is added an 8" extension cord to the end of the EBH cord so that it takes the wear and tear and I can simply replace that section if it dies due to overuse.

    Also, 120F is about what I see with my EBH on these cold winter days, so I suspect it was operating within normal parameters.
     
  3. bedrock8x

    bedrock8x Senior Member

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    Which plug disintegrated, the one from the EBH or the extension cord, or both?
     
  4. Santiago

    Santiago New Member

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    I'll second efusco in his assessment. The first thing I did after installation was to go to Radio Shack and by an 8' extension so that I was not plugging and unplugging into the EBH cord itself.
     
  5. TheForce

    TheForce Stop War! Lets Rave! Make Love!

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  6. jayman

    jayman Senior Member

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    Up here, a common failure mode is the cordset itself. Usually not as dramatically as yours failed, but the actual plug and the first 2-4 inches in from the plug, will go haywire at some point.

    What usually happens is the EBH just quits on you. You're cursing it, wiggle around the plug, and it begins working. That's a reliable indicator the cordset is done

    As a quick fix, I just chop off the plug and wire about 4 inches in, and wire in a HD industrial connector. This is TEMPORARY as the best fix is a new cordset.

    I don't trust those receptacle GFCI's, most don't appear to work reliably. I prefer an actual circuit breaker GFCI, which usually costs $80. For things I plug in, I only use a dedicated GFCI breaker, and when it eventually trips, I know the cordset and/or heater is shot
     
  7. Snagtooth

    Snagtooth Junior Member

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    It was the one from the EBH itself. Now that I read efusco's reply - that's probably what it was, because the thing was stubborn plugging in and unplugging it to the extension cord running to the wall. Makes sense too given the area affected and how the flexible portion melted there.

    Hmmm, now I have to decide if it is worth fixing the cord and paying to get it reinstalled. (Doing it myself will require higher reaching ramps or floor jack to be purchased as I doubt I have anyone I can borrow them from.) The car is usually parked in an insulated (but currently not heated) garage so not sure how much benefit it was giving me now that I am reflecting on the whole scenario.

    So Santiago, how did you "store" the extra length of cord for daily driving purposes? I'm just wondering how to keep that much cord out of the way and not rattling around somewhere behind the grill.

    Oh and yes, I like the behind the license plate idea Force, but again weighing the pros and cons.

    Thanks again everybody.
     
  8. bedrock8x

    bedrock8x Senior Member

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    Since you only have it for several weeks, I would have it replaced under warranty.
     
  9. Santiago

    Santiago New Member

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    So Santiago, how did you "store" the extra length of cord for daily driving purposes? I'm just wondering how to keep that much cord out of the way and not rattling around somewhere behind the grill.

    Not a problem, just coiled it up and secured it behind the grill with a couple of twisties. Doesn't rattle around and I secured the male end to the grill with a spot tie so I can plug and unplug without it pulling out. I used a little bit of WD40 to lubricate the female portion of my cord to the timer to make sure I could plug and unplug it without having to use any force.:cheer2:
     
  10. jayman

    jayman Senior Member

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    I'm not sure I would recommend a petroleum based lubricant for electrical connectors. You can find purpose-built electrical lubricants that are safe to use eg no ignition/flame danger
     
  11. zenMachine

    zenMachine Just another Onionhead

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