First of all, you have to be sure you have the correct matching connectors, S.A.E, Widder, BMW etc.
I was at "Bettys" coffee shop today talking to a guy who sells Widder vests , Widder has a different dual male plug than my Gerbing jacket......
I have a heated gerbing jacket. This is how I hook up my jacket and Heat-troller;
First you get to your battery and hook to the posts a fused two wire connector (matches my heat troller and gerbing jacket) othewise you might have to get wire adapters. I have that coming up thru the the left handlebar loom next to the ignition key. The "Heat-troller" has two sets of wires coming out of it. One has a red tape wrapped around it, that gets plugged into the power side( towards battery), the other wire has white tape around it,( plugs into jacket).
I have my Heat-troller twist tied to the top rear of my tankbag, That way you can look down at it on the road and adjust. Off , no light, click to right slow blink- little heat.....
turn more to right, faster blink- more heat...... solid light- max heat!!!!!
The red wire going back under my map holder and plugging into the front wire near the front of the tankbag.
The white colored end goes thru my Aerostich left hip pocket and gets plugged into the jacket. Then I zip the pocket close and velco shut....
Enjoy, stay warm--Ride farther!!!!!!!!
ZZZZZ