Both of my power locks unexpectedly quit working one day.

I have a 1991 Camaro RS 3.1 with power locks & windows but no power seats or mirrors. I also installed an alarm/remote lock about 5 years ago in this car.

If I push the factory door power lock switches or the remote controlled lock button the only thing that happens is that the relay clicks. Previous to this problem both locks worked fine. I'm not very good at troubleshooting so I need your help.

I'm assuming the locking mechanisms in the doors are fine since it is unlikely that they would both malfunction at the exact same time. I assume the switches are fine since they both make the relay click. Does this sound correct? All other power accessories seem to work.

I found the power lock relay up/behind the drivers side kickpanel. When the alarm was installed years ago I tapped into the light blue wire for lock and the black wire for unlock.

How do I go about troubleshooting this problem?

Your help would be greatly appreciated.

 

Look at the diagram below. For both to not work, you could have an open in the wiring, but I doubt that because they both do not work. First try checking the door lock relay assembly and the 20A acc fuse.