If you have experience and own more than one ball, be sure the a new ball is the same weight. It is difficult to ask your body to deliver two different weights identically. If you are transitioning heavier or lighter, put away the old stuff and get used to the new weight. Consistent delivery will help you control the new ball, thereby control the lane!
It's very hard to abandon potentially effective equipment, but a new direction in ball weight is a BIG decision. Often a GOOD one. But, if your equipment is feeling heavy or more tedious to throw, you may just want to evaluate your fit. More or less pitch forward/lateral/reverse, tighter thumb hole, looser thumb hole (if you gained a little weight and aren't getting your thumb all the way into the hole), are all potential options to regain a secure feel and delivery.
If it feels like your rifling the ball down the lane, a lite ball is very easy to over throw (pull, push, over turn), it is too easy for a minor bump error in your swing to net disastrous results. If you are feeling a little loss of control, to easy to make a mistake, a heavier ball will regain the synergy between ball, swing, approach and your body.