How do i NOT burn out my extraction fan?

Hey all, I've got question that I can really use some help on so I don't trash another fan.

I've got a 2X2X6 grow tent...that's feet by the way for measurement. I have a 465 c.f. fan that just died that was cooling a 400 watt light. The fan motor warms but just doesn't rotate to extract air.

When this fan is on it definitely sucks the tent in with negative pressure which makes me think it was working too hard and burnt out.

I just got a new 400 cfm inline fan and would like to use it properly. Should I just open vent flaps in my tent so the fan isn't working so hard? Thanks for all your help everyone!!

Put fan before light after filter to push thru the hood. Your cooling might not be as effective but your fans will last longer with no heat running thru them. I have metal blade fans don't have an issue and have them pulling

you should open a flap or hole but still the tent should suck in for neg pressure

Your tent should have negative pressure.. but shouldn't be sucked in too far..
open a couple vents on the bottom.. I leave the bottom unzipped..