On a standard SGS headlight. Which is high beam, the top or bottom bulb? Thanks,

 

I’m not sure but I’m gunna guess the one that is lit when you turn on the high beam lol.
Sorry couldn't resist.
On my it’s the lower one.

 

Thanks. When I took the fairing off they unplugged so I just wanted to be sure.

 

Should be marked on the back of the headlight and the bulbs. 55W is low, 65W is high.

 

mine are marked low and high beam too but i changed out the handlebars, and could not remember which was high and which was low. I assume the bottom bulb is the high beam?

2018 Street Glide FLHXS

 

Correct. If you look at the back of the reflector, "65W" is embossed next to the bottom bulb to indicate proper bulb orientation.

 

Hard to believe the plugs are interchangeable but if they are, just connect everything and turn on the power. Shine the light on a wall, if the beam goes up when high beam is selected you were lucky. If the beam goes down, move each plug to the other bulb and try again.