volts reading about 18

C

Cool It

Petty Officer 1st Class
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Feb 13, 2004
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this 2000 Searay I am buying with a 5.7 EFI has a reading of about 18 on the volt gauge while crusing. I am not sure what it reads while at Idle-- I forgot to look! is this ok, because my 1988 5.0 merc reads between 12-14 at Idle and while crusing.<br /><br />thanks<br />Cool It
 
tommays

tommays

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Re: volts reading about 18

i would not trust the guage a good meter is the only way to no the true output but much over 14.5 volts is getting pretty high<br /><br />my guage allways reads 1.5 volts low my meter says its fine<br /><br /><br />tommays
 
P

Peter J Fraser

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Re: volts reading about 18

13.8 volts is the normal charge rate for a 12 volt system. The range is usually upto approx 14.5 as tommays says.<br />Check your output with a known mutimeter. If it matches what your voltmeter is showing then you have a problem with your voltage regulator in the Alt.<br />Take the alternator off and take it into an auto electrician and get it bench tested and serviced.<br />If you keep running your batt at that level of charge you will toast your battery.<br /><br />Peter
 
C

Cool It

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Re: volts reading about 18

is a regulator easy to change out for a non mechanic like myself??? or what should it cost about for a mechanic to do this??? <br /><br />Thanks<br />Cool It
 
Don S

Don S

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Re: volts reading about 18

It all depends on the type alternator. Take it to a starter/alternator shop and have them look at it. It could have blown diodes or bad regulator or other unseen problems. If you did change the regulator, other problems may destroy the new regulator.<br />Cost....... ask the people what it would cost after they find out exactly whats wrong.
 
C

Cool It

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Re: volts reading about 18

this engine has digital ignition, I was told it might not have a voltage regulator. they said it is all electronic. does this sound right??? and I guess it will be put on the computor to test??<br /><br />Thanks<br />COOl It
 
tommays

tommays

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Re: volts reading about 18

and alt is still and alt and i would be Concerned because if its really putting out 18 volts it could start to cook things <br /><br />is this the boat you found upstate ? why wont they take care of it there ?<br /><br />tommays
 
C

Cool It

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Re: volts reading about 18

they are taking care of it I just wanted to have as much info as possible <br /><br />Thanks<br />COOL IT
 
C

Cool It

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Messages
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Re: volts reading about 18

I was reading the meter wrong the top number is 16 not 19 so when I saw the meter up toward the top I thought it was about 18. it actaully reads about 14.5-15 my mechanic says 15 is ok-what do you guys think??? certainly sounds better than 18!!! This reading is from a meter which also matches the gauge.<br /><br />Thanks<br />Cool It
 
S

saltwater_cowboy

Seaman Apprentice
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Mar 27, 2005
Messages
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Re: volts reading about 18

The guage over reads on my friends boat. 15V with engine off, 18V with it running.<br /><br />Checked with a meter an its 13.8 when running.<br /><br />I'd say 15V is too high.
 
Boatist

Boatist

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Re: volts reading about 18

14.5 to 15 volts is ok. It is not going burn up your radios, GPS, or depthfinders. Many newer alternator do charge up to 15 volts and they work fine. In fact I think most new alternators charge to 14.4. Older alternators only charged to about 13.8 volts.<br />Alternator on my truck charges to 15 volts when it is cold. I though this was too high so was doing some checks and reading thru the factory theory manual. In the manual said when the temperature is cold will charge to 15 volts as it warms up the voltage drops to 14.5 volts. At that time I put the meter and tools away and got a refreshing drink.
 
C

Cool It

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Re: volts reading about 18

thanks Guys I think I will be fine!!
 
K

kiwiguy

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Messages
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Re: volts reading about 18

I had the same problem about 3 months ago.<br />My marine grease monkey told me to check the connection of the earth lead. Turned out that was the problem. The meter used to run at about 18 volts at WOT when I removed, cleaned and replaced the lead it brought it back down to 13.5-14v
 
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