95 tahoe remote entry problem

I recently purchased a used remote entry key fob, but my problem isn`t with the remote, I can`t get the tahoe to enter the program mode. It`s a 1995 tahoe, it does have the remote entry option (according to G.M.) The instructions that I`ve seen, that deal with using the test connector don`t seem to apply to my truck, My truck has a 12 pin connector, the instructions are for a 16 pin connector. I`ve also tried the dome light on/off 3 times, cycle the ignition switch, that didn`t work, I`ve tried, hold unlock button down while cycling ignition on/off trick, that didn`t work. Is there any other methods that might work ???? or possibly did I get the other directions wrong. ANY help would be appreciated.

You have an OBD I system, while those instructions are for later vehicles with OBD II.