Charging system.

I have a 1990 fxstc, My battery loses its charge after about a week. I've installed a new battery and checked my stator resistance and output per the service manual. I checked for a ground by lifting the positive battery lead and read about 1500 ohms to ground. I pulled by voltage regulator off the frame and the ground goes away. What should a good voltage regulator read from the positive lead to ground? I have never replaced the voltage regulator. Any help or ideas would be appreciated.

[Mike]

The diode in the regulator may be allowing voltage to leak or bleed off, the service manual has a test for regulator bleed. Based on the year of bike I would be inclined to replace the regulator due to age.
Thanks, Mike