I left port a month ago with rebuilt alternators(one for starter batteries
and one for house). When I start the engine
, typically the volts go up to 14.1 and the batteries
start to charge. It slowly goes down to 13.10 as they charge.
Today when I started the engine
,(my Webasto heater
had just started up on the house set of batteries) I only showed 12.2 to 12.5 tops. Running at 1500rpms on our Ford Lehman
80hp engine. As we motored where we needed to go(no wind
of course) it would slowly go up to 12.5 for a short time. If we reduced the RPMs to 1200, the voltage would go up(strange huh?) to 12.8 or 12.9. and still not make much amps. The "start" battery alternator
is cranking at 14.1 volts. I did have my inverter
on so I could run my computer as I was going through some tricky areas that I needed AIS
info on. I'm sure it took some of my battery
power while it was running but to knock us down to 12.2 to 12.5 seems a bit big a drop. I've checked the belts and they appear to be nice and tight.
The boatyard that I had been in had the alternators rebuilt while I was in dry dock
since they looked quite blackened by belt dust(did I get conned?). There seems to be a good bit of the same black dust on the alternator
Any suggestions on what to do to check the alternators to see if something is wrong? I'm still new to this boating