Alternator and fuel pump on Volvo Penta 3.0 GLP-D

[alldodge]

- on resting battery, from 12 V to 10 V
- on charging battery, from 13 V to 11 V
- on alternator, from 14 V to 12 V.
- Digital multi-meter connected straight to battery shows the correct voltage

A fully charged resting Bat should read 12.7V that is after it has sat for an hour or so off the charger. Once motor has reved above 1500 RPM the ALT should show 14.5V

Now the meter being used may be slightly off

 

[kwanza1]

Apologies, my actual numbers are closer to the ones you mention, yes.
Resting battery - it has taken a battering after all the trials and haven't been recharged yet - 12.4 V
On alternator - idling only, ~800 RPM, on garden hose - 14.2 V

The internal resistance of my bilge blower is 0.6 Ohms. While it seems too low, I will also try to measure the voltage drop on it. All connections are heat shrink wrapped, need to try to get wires into the connector itself.
Thank you.

 

[bruceb58]

Apologies, my actual numbers are closer to the ones you mention, yes.
Resting battery - it has taken a battering after all the trials and haven't been recharged yet - 12.4 V
On alternator - idling only, ~800 RPM, on garden hose - 14.2 V

The internal resistance of my bilge blower is 0.6 Ohms. While it seems too low, I will also try to measure the voltage drop on it. All connections are heat shrink wrapped, need to try to get wires into the connector itself.
Thank you.

Measuring the resistance of a blower tells you nothing. If you want to see how much current it is drawing use a DC clamp meter.

As far as your voltage dropping when you turn on the alternator, that points to a resistive connection between the engine, through the harness up to your dash fuse panel. Check the engine connector first for corrosion in there and then go down the line. Put your negative lead on the battery itself and then measure up the line. You will need a long jumper for the negative lead of your meter. Also measure the voltage drop between your negative terminal of your battery and the negative terminal of your fuse panel with the blower on...you could have voltage drop in the negative side.