To properly set the tension on your RV roller shade and prevent it from unrolling completely when pulled, first carefully remove the shade from its mounting brackets. Locate the tension adjustment mechanism on one end of the roller tube, which usually involves a ratchet or pin system. Increase the tension by rotating the roller tube counterclockwise to tighten the internal spring. After a few rotations, reattach the shade and test the tension. Repeat this process until the desired tension is achieved and the shade no longer unrolls fully when pulled. Once set, securely reinstall the shade onto the brackets. If the shade continues to unroll despite these adjustments, the internal spring mechanism may be worn out, and replacing the roller shade assembly is recommended. You can explore replacement options at Elkhart RV Parts for quality RV roller shades.