What are the F's of the MFS?

[jDolan]

'88 90q
I got mondo bad cold start problems here. Also no temp gauge. Kind of
figured that the MFS was bad, so I decided to check the wiring at the plug,
at least. Surprise! What a nice shade of green in there. Also only one wire
connected! The car does run, though, once perseverance is just about
exhausted. So, I'm wondering what the functions of the 'Multi function
switch' are? As far as I can tell, this one is a NFS.
 Chris at Force5 is going to send me over a plug with a spliceable tail, so
I'm on the road to repair. I didn't think I could fix what is there, as I
don't know which wire goes where, or if it is even do-able. Once that is in
place I'll probably learn I need a new switch, but just what does it do?

jim   '88 90q  w/ 274K miles
Rochester, Vt.