A friend brought me his 08 CTS.... both rear locks were not working..... the front passenger door would not open from the outside. I put new actuators in the back and fixed the problem.... I replaced the actuator in the front passenger.... I thought I had solved the problem.... the passenger front door now opened from the outside...... then I discovered that both front doors would not lock now..... I spent about and hour and a 1/2 tying to discover the issue.... never remedied the problem..... what now??

Does the switch cause the actuator to try to lock and fail or does the actuator do nothing (like with the door panel off and you looking right at it) ?

When you activate the switches you hear a noise, but the door does not unlock.

I'd check for something jammed or the actuator has gone bad and gutted itself.

It'* a brand new actuator I have just put in...when I finished install it did this.

Have you checked for free motion of everything that gets moved by the actuator?