Mercury Voltage

[awilson]

How can I check the voltage output with a multi-meter on a carbureted 1995 200 Mercury? The voltage meter on the dash shows 16+ volts over 4000 RPM. Do I need to check voltage at each coil or is there another way?

 

[rons boat]

Re: Mercury Voltage

Check accross the battery with a good meter of known accuracy. A good digital meter is fairly economical. Older motors without regulators will go up that high but it is not good for the battery and accessories. Without a regulator you need to turn on a sufficent load to lower the Voltage. 16V is too high if yours is a regulator type charge system. 14.3V is the target. Older motors operating without a regulator require you to put a load on the system to keep from exceeding 15V for any length of time. That means turning on something equivalent to headlights on a car. Some boats have dock lights which fit the bill. Most motors of the 1995 vintage did have regulators, so you do need to double check that built in meter with the method above.

 

[awilson]

Re: Mercury Voltage

Thanks for the reply Ron. My engine does have a regulator, but it's definately exceeding 16 volts. Could the problem be something other than the regulator?

 

[ob]

Re: Mercury Voltage

awlison,Check the voltage across battery terminals while your volt guage is reading 16 volts to insure the guages accuracy.In other words ,duplicate the 16 volt reading.If it duplicates you need to address the voltage regulator.That particular regulator has a superceded P/N which leads me to believe there was a problem with the original.They're over $100 so verify overcharge before changing.