Hi - the switch appears to be NOT after market - I will try to upload a pix of it later.Welcome to the forum.
If there's a switch on the body, I would see if a fan has been added.
Look at the underside of the fuse box lid and there should be a label with the info you requested.
The lid from the fuse box is missing (as is the access cover over the battery and fuse box. I was hoping someone could upload a pix of one from my model.