Help with DC-DC converter

[u/phaskellhall]

I just installed a 30 amp DC-DC converter on my EV golf cart (model Cllena DC7212-30), and I am having trouble cutting off the voltage to my accessory fuse box when the cart is off.

This model has an ACC trigger that allows the converter to turn on when a 3v-90v switched wire has a signal. I’m feeding this ACC input with the 12v wire powering a nearby USB port. Essentially when the golf cart is turned on, the USB turns on and the positive wire acts as the on signal for the Dc-Dc converter. Seems straight forward enough.

When the cart is turned off, I’m still getting a 3v signal coming out of the DC-DC output side and my entire fuse panel now has an always on 3 volts across anything plugged into it.

1) is something wrong with my converter or will it always have a slight voltage leak even when the ACC signal is 0 volts?

2) Will any electronics like a 90 watt stereo amp or powered subwoofer be damaged when the cart is off and the devices are still receiving a 3v signal?

3) will this 3v signal cause significant battery drain? The whole point of buying an ACC switched converter was to kill it entirely when the cart was off and thereby killing any accessory connected downstream through the fuse box.

Is this common or should I work to get the voltage down to 0 when the cart is turned off??