Yes you need to release the bars and take it off the ball
if you want total trailer weight.
I pull up so my truck is on the last scale pad.
My trailer tongue and tongue jack and trailer wheels
are on the pad behind me.
I was trying to get my tongue weight as well as total trailer so
I had them weigh me twice. It only cost a dollar extra for the 2nd weight.
Some folks do weigh with the bars tight so they can see how much
of the trailer weight is being sent to the truck - especially the front
axle of the truck.
I weighed 1st with the WD bars released but the hitch was still on the ball.
Then I cranked down the tongue jack and released the ball and got
a 2nd weight.
The difference in the truck weight with the trailer on the ball and off
is my tongue weight.
The 2nd weight of the trailer with the tongue jack down was the total
trailer weight. (make sure tongue jack is on the pad behind the truck)
My 25' Rockwood Ultra lite loaded with half tank of water, full gear,
2 full LP tanks and food in the fridge, ready to go camping only
weighed 4020 LBS.
I think that's GREAT!!!
Dan & Rita D
2004 5.3L Silverado 1500 ext. cab 2WD
1999 Suzuki Intruder Motorcycle
Blue Ox WD hitch, AirLift load levelers
Camping days 2010-53, 2011-47, 2012-41,
2013-41, 2014-31, 2015-40, 2016-38