Need some help... New to the forum.

[Dogluvr]

I recently picked up a 99 Sierra 1500. I just replaced the old tired lock actuators but the passenger side will not unlock. It won't even attempt, makes no noise at all. I applied direct voltage to it and it works fine for both lock and unlock. But when plugged in it will only lock no matter what button is pushed, driver's button, passenger button, remote, etc. I can usually figure this stuff out but I don't know where to begin on this. Every other power option for the locks functions correctly (except the automatic unlock) please advise!! Thanks

[Green 1364]

May be the relay not sending the signal on the wire to unlock to the actuator.

[Dogluvr]

I'll try that. Is that the relay in the small fuse box left of the dashboard? I think it's marked "lock" or something similar.

[Dogluvr]

The weird thing is when I hook up a multimeter to the connector, it reads +12v and -12v when I hit lock and unlock. As if it's getting the right signal

[Dogluvr]

It was the relay!!

[Green 1364]

Good job!