Heater and steppers are fed from the same fuse. I'd be nervous the steppers might act up when the heater PWM kicks in.
Since you already replace the Fets, you could also beef up the power-traces on the PCB?
Scratch off the laquer and solder some extra single strand copper wire to the most stressed traces.
BTW: I'd look for inline fuses from cars instead of the polyfuses.
Edited 1 time(s). Last edit at 08/22/2017 02:36AM by o_lampe.
