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420e it block heater

lmm600 ยท 2017-12-27 16:23

Any one know why a engine block heater on a 420e cat would quit working. It appears to be plugged in at the block. Has power to plug in above battery box. Can they just burn out or is there something I'm missing?

Replies5
  1. #1RDC_580C2017-12-27 16:58

    They corrode and can open up, or burn out, same as the heating elements in a home water heater.

  2. #2Delmer2017-12-27 16:59

    Yes, of course they can burn out. More likely a loose connection, frayed cord, or something external to the engine. Check the ohms between the prongs on the plug, roughly 20-30 ohms if working.

  3. #3lmm6002017-12-27 19:06

    Thanks, I'll try to get to it tomorrow and check resistance.

  4. #4Billrog2017-12-27 21:36

    Unplug the cord at the block heater and check it as well as the block heater itself.

  5. #5lmm6002017-12-29 20:11

    Thanks everyone! After using ohm meter on harness, it seems I have a intermittent bad connection where extension cord connects to the block heater harness. For some reason there is one prong (regular 110v 3 prong plug) that some times works and some times doesn't.