Have a dual battery setup in my 2000 gmc Sierra with an auxiliary battery for my sub isolated through a relay to the other for charging had some issues with the lights dimming so I replaced the alternator with a new 130w and checked the batteries but now my lights stay dimmed and I constantly have the battery indicator on Even without the sound system on along with none of my gauges working is my new alternator just not strong enough or am I likely having a drain in the system?