Which wires going to the ALT. should have power at key on engine off??

With the key on and the engine off the middle wire on the big plug and the power wire have voltage, the small plug doesen't is that how's it's supposed to be?? I took the ALT to autozone and it tested fine, im going to fire up my car this weekend and I repaired a little bit of wiring so hopefuly that fixed my charging issue as the ALT is good, please which wires should have power with the engine off.