This is just begging to be addressed by one of the old hands here....
I was thinking the same.
On my '93 I DID change the battery and now if I'm not close to the drivers side doors it won't work but on the passenger side I can stand far away and it works. Is there some kind of signal boost somewhere on the car?
changing the battery had no effect mine was geeting weaker regardless and in a ~3 week period eventually stopped working as piratebron described. was considering splitting it open and saturating with electrical cleaner and letting it dry completely but that's a long shot that I'm sure won;t work. My guess is there's something electrical in the key that simply wears/gives out after awhile....
The wireless remote unlock in the 90 LS I used to have worked intermittently for YEARS. Shortly after I sold the car in 2003, its new owner found that the ROM chip in the ECU in the trunk on the driver side was not firmly seated. After he snapped the ROM chip in place, the the keyless entry system worked fine.
I'm guessing the ROM chip was dislodged when I hit a bump several years after the chip was replaced. The ROM chip and the keys were replaced under the original warranty shortly after I bought the car due building security systems interfering with the wireless unlock system of the LS. I'm guessing that the replacement ROM chip had not been properly installed.
My 92 kinda worked for a short time than nothing. Replaced battery nothing. Went and had a viper remote entry put in for a $100. Works great and the anti theft will still arm itself like it would with the factory remote. If you want the horn to honk with viper system that thats extra about $40.