Well, unfortunately my car does not have seat heaters, I wonder if the wiring was put in anyhow and they just left the element out. I've tried the white, red, and blue color fuses and they blow immediately. There are only two wires as you mentioned, one red, the other red and white so that's at least good.

I figure that it's been like this since I've had the car, everything seems to work fine on the car except the low speed aux fan setting but I don't think that this has to due with it.

Do you think you can email me the pdf of the wiring diagram?

__________________
1992 Mercedes-Benz 400E
2002 Mercedes-Benz ML500