Well, there are several things one could do, though they might not be easy

The fact that you hear clicking under the dash, which I'm assuming the sound is coming from below the radio, is a possible indicator of a defective Central Lock Relay, and not a problem with the remote as the remote would have to be functioning in order to trigger the clicking.

I'd start by trying the key in the drivers door to make sure that the door locks are functioning. And also a quick look at the dome light to make sure it goes on when the door is unlocked and in general is functioning correctly (both systems share the same complex relay). If either show a problem, first check fuse #2 & #13 in the fuse box under the hood of the car, if that's good then I would suspect a bad Central Lock Relay and you will have to pull the radio and the surrounding trim out as well as take loose the whole center consol/armrest in order to get to that relay.

If all is well above, next you would need to possibly remove the knee bolster or, what ever trim that may be in the way under the driver's side of the dash, as you would need to access the black box for the remote control system. I believe it is located lust left of the steering wheel, it's a smallish black box with a small single plug on the side, the six pins of this small plug are all arranged in a single row. The green/red wire is the main power into the box, the blue/yellow wire is the power going out to the power door lock relay. With the box plugged in, I would take a volt meter and a simple sewing straight pin and use the pin to tap into the blue/yellow wire. Then operating the remote I would check to see if there was +voltage across that wire and ground. If there is no response I would carefully tap into the green/red wire and test for voltage, it should be hot at all times, if the green/red wire is hot and there is no response from the blue/yellow wire, I would suspect a bad black box OR a problem with the remote control. If you do get a response from the blue/yellow wire, then I would suspect a bad Central Lock Relay.

Should you determine that it is the Central Lock Relay I can post a diagram of it's location


By the way, where did you find the instructions for programming the remote?
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'92 240 @45k & '96 960 @41k