Plug under the hood.

I would think it's an oil warmer , did you buy it in a cold climate ?

Engine block heater mostly used in colder regions.

Should I plug it in? I guess I could follow where the cord goes when I have the time.

What part of the country do you live?

I'm in Wisconsin.

You could try it and see if it works. Then I would plug it in when the temp gets below 15 or so degrees F. Those block heaters draw substantial current so use a good quality extension cord of at least 14 gauge and be aware that they will really make the electric meter spin.

Okay, awesome. I will do so. I'm sure it won't get that cold for another month, but I'll do that. Thank you.