I think the red accessory connector in the headlight bucket might be a Sumitomo HM-090 (male, 2-pin).
Have a look at this link
http://www.cycleterminal.com/hm-sealed-series-090.html
About 1/2 way down, to the section "2 pin HM 090 Male and Female locking connector". The male half looks identical (except for the color) to the "cap" from the red connector in the headlight bucket.
I haven't tried this connector yet...will first see if I can find a supplier in Canada so shipping is more reasonable.