Voltage Drop??

[Celebrity268]

Ok, here's my scenario....I just installed 3 new batteries in my boat...the starboard gauge reads 12+ volts, but the port side is showing only around 10 or so...the gauge does work, as when I turn the key the starter makes a quick "click" sound and the port side voltage drops to 0 for a second and then bounces back to around 10. I used a multi-meter and I have 12.5 volts at the starter (from the wire out of the selector switch to the starter itself). Any ideas on what could cause my drop, and if that would be why the starter's not fully engaging? Someone had mentioned to me the slave solenoid, but with the clicking I'm hearing, I assume the solenoid is ok...any help is greatly appreciated! Thanks in advance guys!

 

[Don S]

Re: Voltage Drop??

Typically, if the voltage drops to 0 when even a small load is put on it, you can bet you have a loose or corroded connection or damaged wires somewhere.

10 volts on a battery is a dead battery. Check it with a DVM directly on the battery terminals. Not the nuts or cable ends.

 

[Celebrity268]

Re: Voltage Drop??

Checked all 3 batteries...all three have full power...when i try to start the port engine, only the port gauge goes to 0... the starboard shows a slight drop, as normal when the starter would engage....also have full voltage at all connections on the selector switches too.....def. frustrating....

 

[Bondo]

Re: Voltage Drop??

Checked all 3 batteries...all three have full power...when i try to start the port engine, only the port gauge goes to 0... the starboard shows a slight drop, as normal when the starter would engage....also have full voltage at all connections on the selector switches too.....def. frustrating....

Ayuh,.... Check all the Grounds....

 

[bruceb58]

Re: Voltage Drop??

A fully charged battery is 12.6V. What are yours after you have them fully charged and measured with a multimeter directly on the battery?

 

[Celebrity268]

Re: Voltage Drop??

My grounds all seem tight and clean, but I'll check again...as for the batteries they're all between 12.57 and 12.60...man I hate wiring issues.....I'm assuming a bad engine ground WOULD cause my volt gauge at the panel to read low, as well as hinder the starter...

 

[mark1905]

Re: Voltage Drop??

Definitely a connection issue..

 

[Don S]

Re: Voltage Drop??

Could be nothing more than the main harness plug on the engine is loose or corroded.

Have no clue what we are working on.