Bottom line, the power
device does not send/output wattage to the delivery
device, wattage is the byproduct of x voltage met with x resistance. Lower resistance same voltage = higher watt.
Sending them a picture of it incapable of outputting more than 3v is about all that can be done. Any inline voltage meter or even a multimeter will do that. multimeter - positive lead on center pin negative lead on 510 threading, press button.
I got confused because a few times you've said things like;
" It won't go over 3 watts with anything I put on it "
" How can I show this
mod not firing over 3 watts "
" Any setting over 12 watts does not work "
" It
feels like it won't fire over 12 watts "
" It won't go over 12 watts "
" From 13w to 100, it's firing less than 3 volts "
" The rda I'm using works great at 3.76 watts on my other mods "
I am trying to help, not add to your frustration.
If you're conversing with folks that English is a second language or don't speak/understand at all unless a translator is used it is important to ensure your words say what you mean.
Several have suggested using a lower Ω coil ( like .5Ω ~ .2Ω ) to see if it continues to malfunction. It is a funky clunky device that has a narrow range no matter how it is advertised.