Voltage drop

[1994almeida]

On Volvo Penta 5.0 Gi from 1999, with the engine off, the battery terminals read 12.8 V, and the voltage at console instruments is 11.8 V.
With the engine on, the battery terminals read 14.1 and the voltage at console instruments is 12.8.
Is that normal or something is wrong?
Thank you

 

[Scott Danforth]

first, see if the $3 gauge reads accurately
second, if it does, clean all your connections from the battery to the motor to the helm and back, including the ground buss under the helm

 

[GA_Boater]

Are you reading the dash gauge for the lower voltage or using a meter and probing the power feed to the gauges? If it's dash gauge, instead use the same meter you used across the battery to measure the voltage.

It is normal for some slight voltage drop due to wire resistance, but 1V-1.3V is excessive when using the same meter. Do what Scott said and don't forget fuses and fuse holders. They get grungy too.

 

[1994almeida]

I use the same meter to mesure the voltage at the power feed to the gauges and at the battery.
Thank you

 

[1994almeida]

I have to find the "the ground buss under the helm"??

 

[The Force power]

follow the wires from your dash gauges & you'll find where "the grounds" meet-up