Block Heater stopped working

[cephraim]

I've been using an electric block heater for 8 months now. It's the Nissan version installed by my dealer and plugs right into the block.

Worked great in the winter, bringing engine temp to 100+ degrees in the dead of winter (Western NY).

Earlier this month, I forgot to unplug before backing out of the garage (again!). I have the extension cord tied down so that, when this happens, the cord disconnects from the plug dangling from my bumper. This has not caused any problems in the past, but I'm now thinking I screwed something up, as my engine temp (fWT, measured with SGII) isn't getting above 75 now.

Could I have "shorted" this thing out? They're pretty simple devices, I would think. So, is it more likely that I created an "open" in the plug and will need to install a new plug on the end of the cord? Since the spot where it is installed on the block is so hard to get to (many hours of work that I have no talent to do), I'm looking for easy ways to test this thing without taking it back to the dealer.

Any ideas?

Thanks!
Eph

[MetroMPG]

You're right: block heaters are really simple devices. The problem is either the heating element (they can burn out) or the cord.

It's more likely a damaged plug or cord, based on your description.

You can use a multimeter to test the cord's continuity. I'd recommend wiggling/bending it while doing this to see if you've got a partial/intermittent break.

If you don't have a multimeter, you could plug into a kill-a-watt and watch the current draw reading while doing the same thing (working the cord).

FYI, this thread may give you some ideas as well: Kats heater FAILED AGAIN

[cephraim]

Thanks. I do have a multimeter. But, the problem is, the only end that is accessible for testing continuity is the plug end. The heater is installed deep in the engine in a "frost plug" hole on the block.

Is there something else I can measure at just the plug end?

Thanks for that other link. I'll take a look...

Eph

[DonR]

You could measure resistance at the plug. Call the dealer & ask what the resistance levels should be through the heater. It your plug reads infinite or zero Ohms I would say you have a problem. I have a heater for my suburban I have yet to install. I will measure resistance across heater & heater & cord & let you know tomorrow.

My heaters have a cord that just presses on. If you can feel the cord on the block end you can probably replace it without seeing it.

I have tried to leave the driveway twice while still plugged in. The first was the morning after my 6 yr old daughter asked me if I ever forgot to unplug it to which I truthfully replied "no".
1st time - I stopped in time.
2nd time - cord knotted up in the garage & broke the door on its way out.

I used to just put a loop in the extension cord & put around a tow hook.

Now I tie a loop in short extension cord & put it around a tow hook on the front bumper. Then I plug my long extension cord into the short one. It may screw up an extension cord but will not screw up my heater. The last thing I need is antifreeze pouring out of the block at 6:30 am. You could tie a cord around a tow point by your front bumper.

An LED sign that says "BLOCK HEATER" that is on when the heater is plugged in may be in my future too.

Don

[cephraim]

Thanks. Let me know what you find out. I definitely can't get to the point where it attaches to the block, and it is screwed into the block.