Here's the problem I'm facing. Whenever it's hot outside, my driver's side door lock will not lock/unlock via the driver's panel button or remote, only through the key hole.

I've got an after-market python alarm which locks the doors once the car is started, and that also fails to lock when it is hot.

Now, in the morning or on days when it is cool outside, everything works fine.

Any reason why this is happening and how to fix it? Kind of puzzled and I'm 90% sure it's temperature related (when I bought the car, everything worked, but it was cool outside...).

 

Mine works on and off too like yours.....yeh this is really weird considering it only started about a week ago or so when it started getting really hot :s.

 

It's your door lock actuator..check eBay..