[wiswind]

If you have a 1996 through 1998 3.8L, then you have the vaccum version.
Double check the vaccum connections and the electrical connections.
It is possible that one of the actuators is getting weak......or starting to leak.
In that case.....I would wait until the problem becomes more solid....so that you can troubleshoot to find out which one is leaking.
1 can leak and cause the other one to not work.......and they are too expensive to just throw one in on a guess.
They are different......for right bank (rear) and for left bank (front), so you cannot buy 1 and try it in both positions.

If they fail.....you can unplug the vaccum line from 1 actuator and quickly put a finger over that vaccum line....and see if the other one works.
If not.....then the one still connected is the problem.
If it works.....plug the vaccum line back in......and repeat the process with the other actuator.

However, these test instructions are only going to help if you have a solid failure......