Raspberry Pi Stack Exchange is a question and answer site for users and developers of hardware and software for Raspberry Pi. It only takes a minute to sign up.
Sign up to join this community
According to this website: https://pinout.xyz/pinout/pin2_5v_power#
The +5V GPIO pins can push up to 1.5A of current, and are attached directly to the Pi's power supply.
My question is, if I use both +5V pins and connect them in parallel (using diodes just in case), could I draw up to 3A assuming the main power supply is sufficient?
The 5V pins are already connected (and also to the on-board 5V rail - which, depending on model, is NOT "attached directly to the Pi's power supply").
Using both will make NO difference. (Strictly there will be a minor reduction in resistance, but as this is negligible it would be impossible to measure.)
Note the pins do not push anything! The current drawn will be dependent on load.
No you cannot draw 3A. Depending on Pi model current is limited by polyfuse, and some is needed to run the Pi itself and attached peripherals. See Raspberry Pi Power Limitations
Attempting to draw heavy currents is likely to overload the thin copper traces on the board.
