Honda ATF return line?
 

Which is the return line on most Honda automatics? I have a choice of 2 on my fiancee's 09 Fit AT. There's a big long line on the driver's side running over the transmission that gets really hot. I'm guessing this is the feed line. There's also a much shorter line that stays pretty cool to the left of the big long line. I'm guessing this is the return line.

The cooler of the two lines after a "spirited" drive will be the return.

You can also check by starting the car in neutral with one line disconnected... the return line won't spurt fluid out under pressure, although some may still come out.

If there are two different sized lines, I believe the smaller one tends to be the return.

You guessed correctly.

Thanks!