Checking CEL Codes

I got a 95 jetta , obd port 2 but its obd1. I am trying to read the codes with a paper clip. Ive looked at a hundred sites and i know i am doing it right. short #4 and 15. When i do this it turns the cel off. I have to turn the car off and on again for the light to come back on. Ive tried it with car off , car on , and car ignition on and they all do same. I heard something about a radio harness and im thinking maybe thats my problem since i dont have the factory radio and im doing everything else correctly. HELP!