i searched but didn't find the answer to my question.
i ordered the engine block heater on my 08 Rubi. i plug it in every night , no problem there. WHEN DO I UNPLUG IT??? i know this sounds stupid, but will it harm the engine or any part of the jk if i start the jk in the morning and then i unplug the block heater?
thanx for your wise wisdom. sry if it's in the manual... i get very frustrated searching for an hour to an answer i know all of you know already.

 

I didn't get the engine heater but I would think it would be best to unplug it BEFORE starting the engine. I don't think it hurts anything to start it while plugged in but it would be more convenient to unplug it first. 1st off you don't have to get in, start it, then get out, unplug it, then get back in. Also as rediculous as it may sound there is a chance you can forget to unplug it and drive away while still plugged in.

 

Plug it at least 1 hour before starting the engine. You can plug it also 12 hours, it's not a problem. UNPLUG IT before starting the engine, and remove the wire.
DON'T FORGET TO REMOVE THE WIRE! Each year, I see at least one car on the highway with the wire in the rear following the car

 

I've heard that you should unplug first, then start the vehicle, but I've never been told why. I've never actually heard of any damage caused by starting while it's still plugged in.

Personally, I'll often start the Jeep, then unplug it while I'm out brushing off snow/scraping frost or whatever. I'm very paranoid about not being "that guy" with the cord hanging from the front of the Jeep.

 

I have a timer for mine, so when it is plugged in the block heater doesn't even come on until 5am, about 2-3 hours before I leave the house. I also back into my driveway and I string the power cable across the driver side mirror and the front grill. I'll start the Jeep and grab the snow brush/ice scraper and get out to clean the Jeep and disconnect the block heater all at once.

 

I unplug mine before starting just to be safe, but I don't think it would hurt if you started it plugged in (don't quote me on that). The only thing that could happen to your block heater if you consistently leave it plugged in for long periods of time is the element could burn out.. which would suck

 

i am embarrassed to admit this, but i did this ONE time last year. my first winter with a block heater on any vehicle. was on the cell phone, walked out, jumped in, backed up and POP! it unplugged itself and luckily didn't hurt anything

 

that is a great idea: running the power cord around the mirror, kinda like the winch control. mine is yellow, so i couldn't miss that! thanx!!

 

The instructions that came with the block heaters I have installed have all said don't have it plugged in with the engine running. If an air pocket goes by the element, the heater will burn out in a hurry.
And, there is no reason to start engine, then unplug.

 

Hi! I have the power cord draped in such a way that it blocks my access to the drivers door so I have to unplug it first or get tangled up in it. Just my way of insuring that I don't accidently drive off with it plugged in. Take care... Mike