Voltage problems....

[synack]

This spring I replaced a bunch of things in my boat's charging system. I put in a new 130 amp one wire alternator, a Charles 130 amp two battery isolator, new 4 guage wiring between the alternator/isolator/battery switch, and two new duralast batteries.

When I first installed the system, the guage (both in the dash and on the GPS) showed that I had 11.3 volts. I know that isolators impart a voltage drop, so I assumed this was normal. However, this voltage is slowly dropping over time and I now show 10.9/10.8 volts on the guages.

The last thing that I want to have is dead batteries and get stuck somewhere.

Any ideas on what might be wrong? Anything that should be suspect 1st?

I'm thinking about bypassing the isolator and seeing if that might help any.

[MOP]

Take the input lead off the isolator and run it direct to one of the batteries, if it voltage comes up you have a bum isolator if not the alternator may not be putting out properly swap the bad part for new.

Phil

[synack]

I finally got a change to work on the boat yesterday. I bypassed the isolator and put the alternator positive lead right onto the starting battery. Last trip out I was getting 10.9V according to my GPS. This time it was up at 12, but after revving it for a bit and driving, it dropped down to 11. So I'm going to try putting back the old stock alternator.