High Voltage?

1996 Merc 150 Off Shore. When running over idle my voltage guage is pinned. Should I replace the voltage regulator first?

Re: High Voltage?

get a manual and follow proper test proceedures<br />for things like voltage regulator. don't throw<br />parts at problem until u know what's wrong.<br />could even be a faulty gauge...

Re: High Voltage?

To add to that, get ya a test meter(Voltmeter) and check at the battery what voltage you are getting. That would isolate the gauge if it's reading incorrectly and give you a true reading.

Re: High Voltage?

I have 2 of the same engines, I'll put money on it, that is those poor quality, very expensive voltage regulators and there's 2 of em on each engine. I've replaced all 4 , and again have at least one acting up again. Mercury has changed the specs on these things numerous times, maybe the ones they offer now are right. Let me know if it turns out to be the same thing for you.

Re: High Voltage?

I've check the batteries and there good. My fish finder and GSP logs show high voltage shutdowns. <br /><br />I need to replace the wiring harness on the motor, is factory gear the best way to go? Or are there after market companies for tese parts?<br /><br />Also, Thanks for the feed back. I'll let you know if the regulators fix the problem.

Re: High Voltage?

Did you check your stator coil resistance? Unlikely its the problem, but if it is, then the new regulators will fail again and that's about $130 apiece wasted. I believe the spec says they should be between .2-.45 ohms.<br /><br />I just replaced both of my VRs as well ('96 Merc 175EFI). One had exploded and leaked resin all over the leads.<br /><br />While we're on the subject...<br />I noticed they've added a new ground lead to the replacement regulators. When I pulled the old ones off, I noticed some kind of grease on the backside mounting surface. Anybody know the purpose for the grease?<br /><br />1. Dielectric for a better ground?<br />2. Thermal conductivity?<br />3. Corrosion protection?<br /><br />Kyle

Re: High Voltage?

Originally posted by soonerbred:<br />While we're on the subject...<br />I noticed they've added a new ground lead to the replacement regulators. When I pulled the old ones off, I noticed some kind of grease on the backside mounting surface. Anybody know the purpose for the grease?<br /><br />1. Dielectric for a better ground?<br />2. Thermal conductivity?<br />3. Corrosion protection?<br /><br />Kyle

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Kyle, The answer to your questions is yes to 1 and 3 no to #2. That grease provides corrosion primarily and as a dielectric secondary. When you replace the ground wire, make sure it is clean and corrosion and grease free. After you install the ground wire, use a liquid neoprene or silicone (cringe, I hate that crap!) to seal the connection. Good luck!

Re: High Voltage?

The guys at the dealership didn't seem to know. Thanks d.