Would probably been better if you posted this question in the MKIII Forum, but I'll bite.
The headlight wiring harnesses are the same for OBDI and OBDII MKIII Jettas and Golfs.
Just unplug on the radiator core support and swap. Inspect the wiring harness that you're installing for bare wire where the harness bends or there are supports for the harness, I have seen many headlight harnesses with cracked or worn-through insulation AND electrical shorts.



