1994 Mercury 175hp Voltage Question

[NYLaguna2100]

Hi All, <br /><br />I've noticed this weekend that the volt gauge on the dash goes on with the key but does not register charging when the motor is running. Lastnight, I checked the batter with a charging meeter and it is showing 13 volts, so the motor is charging. Another thing is that, my tach doesn't work, and verified it does work on another boat. On this engine, I've noticed there are 2 voltage regulators. Could this be the problem? How do you test them, and how do you tell which one is bad. Any suggestions, much appreicated. Thanks, Chris

 

[sangerwaker]

Re: 1994 Mercury 175hp Voltage Question

The gray wire from the upper voltage regulator is what drives your tach. Try switching the wire to the lower regulator. The gray output from that is not used. If your tach works after this, you need a new upper voltage regulator.

 

[NYLaguna2100]

Re: 1994 Mercury 175hp Voltage Question

Great, thanks for the feedback. Would this be a cause of the volt meter on the dash not registering as well? Thanks again.

 

[sangerwaker]

Re: 1994 Mercury 175hp Voltage Question

Not sure on that part. Post back after you test.

 

[NYLaguna2100]

Re: 1994 Mercury 175hp Voltage Question

Update:<br /><br />Since my tach was not working and the volt gauge not registering, I unpluged the grey wire from the upper regulator and plugged it into the grey wire coming out of the lower regulator. That made the tach work somewhat. If I rev up the motor it would work and then idle around 650, then all of a sudden drop to 0 and not register, then rev, back to around 600, and would be fine. Then if I revved it while at 600 it would jump up to around 1k, not not much more than that even though I could tell it was more than 1k. Where do I go from here. In addition I put the volt meter on the battery while running the motor and is registering around 12.9, but doesnt raise if I rev the motor up, doesn't move at all just stays at 12.9. Still would like to know why the volt meter will not show volts charging and why tach won't work consistenly. Any feedback much appreciated. Thanks

 

[NYLaguna2100]

Re: 1994 Mercury 175hp Voltage Question

Bump, any additional feedback appreciated.<br /><br />Thanks

 

[NYLaguna2100]

Re: 1994 Mercury 175hp Voltage Question

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