[PSUscaper]

It sounds to me like the truck isn't charging the battery at all.

I had a dump trailer for close to 5 years......the only time I had a problem was after about 3 years when the batter went bad and I had to get a new one, or the terminals would get corroded/loose and need to be replaced.......when fixed it worked fine, dumping all day long.

Are you sure the truck power harness has a power lead??? The trailer should charge while hooked to the truck, and keep itself replenished. It sounds like a wiring problem or a bad battery, which after 3 years sounds right.

Also, know with mine, the battery box wasn't great, and the battery would bounce around a bit, especially being a trailer. That tends to shorten the life.

I would check all your wires too. I kind of forgot this one. At the battery terminal, at the pump, at all the leads from the battery to the pump (ground and hot) the connections would go bad. The terminals would melt after about a year, and I would replace them and have a spare on hand all the time. Make sure they are very tight, as the draw is very high for the hoist and they will heat up fast.

And by the way, keep that trailer if you can. I have a dump now and I still wish I had the dump trailer. It is just too handy and I can't count the number of times I wish I had it still.

I would check all your leads and make sure they are tight and corrosion free. This may be part of the problem as to why the battery is discharging so fast and not letting the truck keep up with it.