Oldblue

No it’s not , have you inspected the back of the HVAC control panel in the water fall under the radio, look for melted or burnt connections

donbrew

You might have a look at the back of the speed selector for fried wires.
The cabin air filters do get clogged and soaked if the butyl patch leaked. Nobody ever changes them.
I have no idea what a ground might have to do with overcurrent, other than somebody thinking the switch switches the hot side and splicing into the wire. Or, using that wire for a LED ground.

ALL of those "extra ground" Facebook solutions are junk, don't do it. They can cause your exact problem, If there is a ground problem just fix it.

RJ_RS_SS_350

Have you inspected or tested your fix on the butyl patch (cowl seal)? Perhaps it started leaking again.

PulpFriction

Chevys have been frying resistor packs for at least 30 years. "Good enough" mentality apparently. This is such a simple system. It could be bulletproof. The resistors can't take the heat as installed. It could be much more reliable with better design and QA.

For sure, if you find yourself with a bad resistor pack a second time, don't buy the same brand.