please help with dwell meter

i have a RAC maxi tune meter i can measure points ,dwell ,tach, amps and volts with. its been awhile and i forgot which wires go where and i am hoping someone is familiar with this instrument. ----it has a positive and negative lead with big clips , which im assuming go to the battery. it also has a big clip lead in a big yellew rubber cone. all 3 of these wires go into the instrument in one cluster. then the other cluster going into the instrument are one black and one red wire connect together by a flat metal bar with some type of attachment screw on the end. i know how to use the instrument------i just spaced on the hookups . help would be greatly appreciated. any timing tips too would also be appreciated. thank a bunch. steve