I think this is a mechanical cable, like a wire inside a sheath, that opens the door. The word "chicote" is used for this type of device in Mexico (you don't say where it's from) to describe different things including the speedometer cable, which here it is not.

I am pretty sure it is not the "accelerator cable" because the context indicates something very different though the word could apply to it, and it would not refer to the "harness" either, because in Mexico the term used would be "arnés", and "chicote" would definitely not be used for that.

So from all the above I conclude "cable".