Power problem

SeaHare

0n my 01 310, the port voltage meter always reads about 13V (good) and never really moves much. The SB meter reads about 12V and if I put my blower and Nav lights on it drop to like 9V. This is even with the engines running. The major problem im having is if I have the blower and nav lights on, my VHF will not transmit, assuming it does not have enough voltage. If I turn everything off, it transmits fine... i keep thinking about just rewiring the VHF to my house batteries but i would like to correct the trouble if there is one... If i remember correctly, this has been a problem even when the batteries were new.  Thoughts?

Stodge

I had voltage problems on my previous boat that turned out to be poor connections in the helm.  In my case, there were several things plugged into a one-to-many spade connector on the ignition switch.  The one-to-many connector had worn out (spread and did not make good contact).   The effect was low voltage on the gauge and my VHF kept giving a low voltage error.

Might want to inspect your electrical connections in the helm.

Michael T

I agree with Stodge and I'd also look at the associated grounds. Few problems rob power like loose and/or corroded grounds. Let's hope that's it, as other causes (batteries/charging) are more expensive.