high voltage alarm

[StripaChaser]

I have a 1986 Merc 150 Mariner with oil injection. Recently, I have been getting a high voltage warning on my depthsounder and my volt meter is showing 16+ V at 4000RPM. I got an engine warning horn sound while at 5000 and had to bring the engine to idle. I am thinking the voltage regulator is shot on the motor and will need to be replaced. Any ideas on how to test to make sure this is the root of the problem? Thanks.

 

[Trent]

Re: high voltage alarm

Depends on which model you have as to if you have a regulator. Some models just had a rectifier with no regulation. Try loading the electrical system by turning on a bunch of things. All lights and see if the voltage drops. Keep your voltage below 16. If you dont your going to blow the powerpak on the engine. If it truly does not have a regulator you will need to pay attention more to the water level in the battery. Also some models had a kit available to add a combination regulator/rectifier.

 

[Skinsk]

Re: high voltage alarm

I have found that loose battery connections can cause a high voltage reading like you are describing. Make sure the battery connections are tight (use pliers on wing nuts) and clean. <br /><br />But a problem with your charging system (charges the battery) will not give you an alarm. The battery charging system, rectifier, or voltage regulator is independent of the ignition system. Any alarm you got should be addressed as a separate problem.<br /><br />Scott..

 

[grandx]

Re: high voltage alarm

If you have regulators on that motor, at least one is bad, they have (2) each. I don't know if that motor had regulators, my 85 Mariner 175's did not.

 

[AndyL]

Re: high voltage alarm

I had the same problem which only came to light when I fitted a furuno fs 6000 depth sounder. It operats on a small voltage range and will alarm at 16 volts. My engine had 2 voltage regulators and by disconnecting one and testing across the battery with the motor running it didn't take long to figure out which reg was down. A new VR fixed it and now voltage steady at about 14.6 maximum. You would have to check with your manual as to what your particular motor / charging circuit is. Voltage reg for V6 in uk is about £180 about $250 I suppose so make sure it is at fault before investing.