Are all MB seats wired for heat, regardless if the option was picked to have heated seats?

I was thinking if that is the case to connect my front seats up for the winter.

I've got the 240d (83) and 350sdl (91) I would like to hook bck up.

__________________
71 220D 169K wrecked
83 240D 118K sweet 4 speed
91 350SDL (one of the 60% good engines) 156K
84 300d (loaner to my sister) 189K
79 300SD (partswagen)
86 420SEL partswagen
70 220d (partswagen)
68 280s GASSER!!! under construction now
85 300sd 310K miles winter beater car retired
93 300d 2.5 turbo 168K wife's car
83 280SL euro 5 speed 155K
69 250S newest project 54K