My 98 D16Y4 sedan Central locking on the driver side normally works fine with my aftermarket alarm remote, but if the car is sitting in sunlight and the weather heats up, the drivers side front and back door locks stop working with the remote and I need the key to lock the front door / rest of the doors and often have to open the back door to press the lock down.
In cold weather all the locks lock correctly as they should with the remote. It was the drivers side back door that started having the issue and then the drivers side door started.
The only extra item I believe was added when they added the central locking to the alarm remote was a solenoid (i think its that or a relay). If I can remember this item was needed by the alarm to hook it up with central locking.
Please note that as its an Aussie car, the drivers side is on the right as well
Any ideas on the above issue would be greatly appreciated.