Whalersailor18

I have the 2010 SCrew Lariat with rear defrost and heated mirrors. I noticed the other day when we were riding around digging people out of the 2nd blast of 18 plus inches of snow that whenever I activated my rear defrost, it works fine, but then if I went to turn it on again, it would not go on. I assume it has a timer so you can't overheat the elements, but wanted to be sure.

On a side note, I was able to get around town when most were not able too. I loaded 200 pounds of salt in the back and was towing my trailer with Kubota Loader and a snow blower around while remaining in 2wd most of the time. I only had to go into 4wd a couple of times. Great truck for getting the job done. Attached is a photo of my driveway after I drove out of it the first time to see how the roads were.

steenbag

I had a similar problem with my rear defroster not working a few weeks ago. It turns out that the defroster won't work if the rear window is open, and I guess I had opened and not quite closed the rear window. I pressed the close button to make sure it was closed, and voila the defroster worked again the next time I tried it.

Abn150

The owner's manual talks about the rear window having to be closed on page 71:

"For vehicles with a sliding rear window– the defroster will be disabled when the window is opened."

But nothing about a timer. I have not had that problem with mine not activating the second time.

Whalersailor18

And that would make sense because I did in fact have the rear slider cracked open to let fresh air into the cab. I suspected something like that or the timer, but was just too lazy to go and thumb through the manual to look into it. Thanks again, that is another reason why this site in so great. A group of people with similar interests and answers.