[RealAwesome]

Hello everybody, I've been fixing numerous things on my car and the latest was my passenger mirror. I fixed that. So I had put the door panel on and plugged in the lock and window buttons, I tried the windows, they worked. but when I tried my locks the passenger side thunked, but my driver side had a lighter thunk and didnt go down all the way. Well I tried about three more times and it just got lighter and quit moving. Now when I try it, the passenger side works great but theres no sound or movement from the driver side. Also when I lock and unlock with the key it is much more difficult to turn compared to the passenger side. All help is appreciated.

 

[Blt2Lst]

Sounds like you will need to replace your door lock actuators. I had the same problem and that fixed it..
They are held in place with 1/4" rivets which must be drilled out to remove the actuators. The kit comes with new rivets but you will need a big rivet gun to set the new rivets. Luckily we have one at work so it made it easy. My old actuators were held in with small bolts (they were replaced before) and you might want to go that route if you do not have the rivet gun..

1979-93 Mustang Door Lock Actuator Kit by 50resto at LRS - Same Day Shipping!

 

[LRSjmac]

Hello everybody, I've been fixing numerous things on my car and the latest was my passenger mirror. I fixed that. So I had put the door panel on and plugged in the lock and window buttons, I tried the windows, they worked. but when I tried my locks the passenger side thunked, but my driver side had a lighter thunk and didnt go down all the way. Well I tried about three more times and it just got lighter and quit moving. Now when I try it, the passenger side works great but theres no sound or movement from the driver side. Also when I lock and unlock with the key it is much more difficult to turn compared to the passenger side. All help is appreciated.

Blt2Lst is correct, definitely an actuator. Here is a little write-up that goes over the replacement process, that way you know what you're in for.

79-93 Fox Mustang Door Lock Actuator Replacement - LRS Blog - Read Here Shop Here