I have reinstalled my aux battery system, with my starting battery as my aux
and a new starting battery. However, trouble is on the horizon!
The system mimics the original factory system with a relay connecting the
two batteries when alternator current energizes the relay. However,
apparently the following is happening:

With either battery connected to the relay, continuity can be measured
between pin 87a (Aux battery) and 85 (Relay ground) or 30 (Starting Battery)
and 85 (Relay ground).
If Aux is hooked up, aux goes to ground. If Start is hooked up, start goes
to ground. If both are hooked up, power goes to ground. It goes to the
ground at a rate of 2 amps. Thus, my recently installed 2 amp solar panel
has saved my batteries from being damaged, but I have removed the system for
now.

With neither battery hooked up, there is no continuity between either pin
and the ground pin.

I've never seen a relay fail like this before. Is this common? Is it just a
matter of "replace the relay"?

Thanks!
I'm a bit confused, so any help would be appreciated.

-Craig