Thanks for all the replies...to date I have tried 4 different motor actuators. Thru trial and error what i have discovered is power is getting to the electric acuator but for some reason the lock pops up and pulls back down when utilizing the key in the drivers door. Also, when the door is open and you work the handle it pull the lock door as well. I'm at a lost. It's almost like no DC power is getting to the actuator on the reverse for unlock.

The previous owner did have an amp booster attached to the door panel and i discovered while replacing the rear light assembly there is a red/orange wire cut in the wiring harness and another red wire looped in, i assume was for the amp. I 'm wondering if the red/orange wire has something to due with the DC power to the lock actuator? Since there is power to the actuator and the piston moves when activating the drivers door I'm unsure on the situation with this wire and have not stripped and tied back in due to risk of blowing fuses.

Any and all suggestions would be appreciated. Almost ready to surrender on this one and stay with the secondary key for getting into door.

 

Check this out!!
There is a little spring in the lock mechanism that goes bad.
Our Discovery I had the same problem.
I took the latch out and ordered a set of springs from this guy in the UK.
These are round springs which if broken, the latch will be inoperative.
They are HARD to remove and get in.
Want to kill of 4 hours..?
Well, here you go




discovery lock springs | eBay

 

You were correct!!! And I will never, ever, do it again. What a pain in the @##! But it is fixed and working and thanks very much for pointing me in the right direction.

 

My rear latch has been doing the same for quite some time. I just decided to deal with it when I took everything to bits and realized it wasn't the actuator but the actual door latch itself. I'll just grab a few latches when I goto the junk yard next.

 

I replaced my all of my door actuators ($40 total) which worked great for the first week, and then the locks woud unlock but drop down just enough that i either use the key or pull the tab up...

Springs next from the sounds of it

 

ebay search land rover discovery door spring
fixed my rear door by replacing a colapsed spring and i had the exact same issue. you may see a dangleing spring on the outside of the lock mech or no spring at all (missing) The springs are $4 each. the job wasnt too hard. a door pannel remover, some colored sharpies, large and regular head phillips drivers. pay mind to the linkage installation.
good luck
please report back with what you find