Ditto on the need for brake controller. The brake controller unit needs to be in easy reach of the driver. On most brake controllers there is a lever that you would throw to activate just the trailer brakes -- most
important if your tow vehicle (TV) is in control but the trailer is swinging wildly behind. Instructions for calibrating a Tekonsha Prodigy are to motor up to 20-25mph, take your foot off the gas and throw the manual lever hard over. Properly calibrated, the trailer brakes should bring the combined TV-trailer almost skidding to a halt.
I can't say I can hear a 'click' very well. I do wish to credit overlander64
for a test to make sure your brakes are working. We should expect this on a new unit, but you'd better be sure on a 1966! For my Argosy I turned a plastic bucket upside down and placed a standard magnetic compass as close as possible to the inside
of the brake drum area. Check each side of your axles --- there should be a little needle swing when your test partner puts their foot on the brake pedal inside the TV.
If you get a Tekonsha Prodigy, Jack Canavera
has cautioned that you should not test-pull your breakaway switch with the umbilical attached to the TV. It might burn out the Prodigy every time!!!
And it is for reasons like this that many of us have stepped up to support these Forums. The value is absolute! (click on the 'AIR' Stickers link at the upper right if you wish to see more)