99 Bravada AWD
 

what is the best way to test if the AWD system is working properly? all i did so far was top off the fluids and jacked up front passenger side tire and try to spin freely which it did not

I would say put all 4 corners up in the air then drop one front one onto the ground. Now put in gear and let idle. Should turn both rear wheels and the front one thats up in the air will turn slowly but it will be jerky not smooth like the rears. When you lift the one thats on the ground it should start to turn slowly as well.

Or with all 4 wheels off the ground and the truck in neutral when you turn the LR the RF should turn as well and the RR will turn backwards of the LR. And vice versa.

What is making you think its not working properly?

Keep in mind that AWD and 4WD are nothing alike and do not perform the same.

yes i know they are not the same, i know you cannot control when its in 2wd or 4x4 and when one tire loses traction it takes power away from one wheel and puts it to the one losing. i just wanna make sure shes gonna plow through the snow for the upcoming winter

no reason to suspect its not functioning. just got the vehicle and wanted to check, i have a light on the dash that says "service AWD" and its NOT lit so its probably working properly