been there, done that.I inadvertently tested mine leaving a campground last year. Rounded a sharp corner and the truck stopped dead! The wheels rolled off the pavement a bit so I tried to just gas it thinking I was just stuck in the mud - nope, felt like I was tied to a tree, LOL. Then, I thought maybe I hit the concrete post on the corner - nope, turns out the cable snagged on the 5th wheel hitch and pulled out. Embarrassed that it took me more than a few minutes to figure out what really happened.
On a side note, I found a better way to route the cable to avoid a repeat!
I'm not sure why you would expect a "hum" at the trailer wheels. The hum you are likely referring to is when a contactor/relay/etc that is powered by 120VAC is operating and is commonly referred to as a 60 cycle hum......the frequency of the 120VAC. Brakes on trailers are 12VDC systems and there is no "frequency" or cycles per second.....thus the name Direct Current.Pull the pin for the breakaway switch and you'll hear a "hum" at the wheels of the trailer. If you hear the "hum" your brakes are working.
Now, unplug the umbilical cord from the truck, pull the trailer forward while hitched. If you feel the trailer resisting to move forward freely, you KNOW the brakes are working.
It's just that simple.
But has little bearing on the braking ability. The compass merely indicates a magnetic field is nearby.Just hold a compass near the wheel and pull the pin - the magnetic field will affect the compass needle...
If the brakes work when they're activated by the tow vehicle they'll work when they're activated by the break-away witch.But has little bearing on the braking ability. The compass merely indicates a magnetic field is nearby.
True, assuming your switch contacts are in good condition.If the brakes work when they're activated by the tow vehicle they'll work when they're activated by the break-away witch.
If they aren't you won't get a strong magnetic field at the wheels.True, assuming your switch contacts are in good condition.
There can be a strong magnetic field, but if the brakes are not properly adjusted they may not perform well enough to stop the trailer themselves. When the tow vehicle is stopping it also slows the trailer, so weak trailer brakes might go unnoticed until a panic stop is required.If they aren't you won't get a strong magnetic field at the wheels.