My son has a 1993 s10 blazer and we want to determine if it is already set up for remote keyless entry. We bought it used and it didn't have a key fob with it but it has pwr win., pwr dl and an push button on the dash for the back window above the tail gate. I believe it is already set up for keyless, all we have to do is get a remote and program it. My son say it's not that simple. How do we find out if the vehicle is already set up for remote keyless entry