door lock glitch

As always, Thanks in advance for any help you can contribute.
1994 SL
I have had this car apart for a color change/repaint.
When purchased the SL it did not run so I have no idea whether this is something I did or if it was a previous issue.
Now that she's running and reassembled I'm trying to work out the gremlins.
The door lock button on drivers door actuates lock on passenger door but it does not stay in the lock position. It automatically unlocks.
No noise is heard coming from drivers door solenoid and lock slide does not move. It is stuck in the lock position only and can not be moved by hand.
Door lock button on passenger door has the same result.
Therefore the passenger door is always unlocked and the drivers is always locked.
To open the door from the outside I have to turn the key and lift the handle at the same time of the door re locks.
I picked up a lock solenoid from the pick a part and installed it yesterday thinking that was the issue but it has had no effect.
I did not remove the latch, solenoid or inside door handle when I had the door off and apart for paint.

EDIT.
Sitting here, I just realized this problem started after the radio was installed. Bought the car with an empty hole there and bought a factory radio from a friend. Got the code from Mitsu.

thanks again

The 97 I just got does something similar. I believe the issue I have is an aftermarket alarm issue, but have not dug into it. When I turn the key to unlock the solenoid unlocks,then quickly locks over and over till the key is released.

Sorry not much help, I hope you figure it out.

There are two possible issues with the door locks:

1) The inside lock slider can't be moved, the latch appears to be jammed

This is a failure in the latch mechanism. There is a rubber pad in the mechanism that degrades and when it does so, the metal arms in the latch bind up. To fix it you have to replaced the rubber pad inside the mechanism to create the "space" between the metal arms.

2) The inside lock slider can move but moves back. This is also known as machine gun locks.

This is a failure in the actuator mechanism. Again there are rubber pads inside the actuator that fail over time and cause the actuator to stick in one position. You have to open it up and replace the rubber pad.

There are threads about both of these on this site and the other site.

thanks for your input.
I don't think either of these issues is the case.
I did not have this issue until I installed a factory radio.
Something electronic is activating the solenoids.

Any more advice out there?

Go read the threads. Your radio install is unrelated. Most likely you have the actuator problem.

Also, if the key is in the ignition and the door is open, you can not lock the doors. Press the lock button and it immediately unlocks again. if your key is not in the ignition, and it's not staying locked, then refer to the above... But you didn't say whether you had the key in or not, so tossing it out there :)

EricB