low voltage
Printed From: CorrectCraftFan.com
Category: Repairs and Maintenance
Forum Name: Boat Maintenance
Forum Discription: Discuss maintenance of your Correct Craft
URL: http://www.CorrectCraftFan.com/forum/forum_posts.asp?TID=42192
Printed Date: April-20-2024 at 3:48am
Topic: low voltage
Posted By: 797nautiqe
Subject: low voltage
Date Posted: December-01-2017 at 12:04pm
| So i have an 02 SANTE with the 496. When the boat is idling or pulling someone the voltage never gets above 12.5 volts. I believe the gauge is good because when the ballast pumps are used it drops to like 10-11 volts. When they are shut off it goes back to 12 ish. The batteries are both new this year. I have had the alternator checked and it tested good. Its a 70 amp alternator. I've checked the wiring and it all seems to be good, no loose connections or bad spots. I turned off all the equipment that would pull power and still the voltage never goes above 12. In previous boats it is usually around 14 volts. What am I missing if anything here? Any info would be great! Thanks |
Replies:
Posted By: phatsat67
Date Posted: December-01-2017 at 12:23pm
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That was a common problem on 01-04 ish boats that had ballast pumps etc. Most likely the wiring isn't up to the task of supplying all of the accessory pieces with power at one time. You'll need to run voltage drop tests on the entire system starting at the engine/alternator and working your way forward then to the accessories pulling the amperage. Never really remember hearing a for sure fix from Nautique but I know some boats were bought back over the issues. Pretty neat to see a 496 Python. Please post some photos of the engine. |
Posted By: Duane in Indy
Date Posted: December-01-2017 at 12:26pm
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Get out your VOM and get an accurate check. At idle and them at 2500 rpm. Check at the terminal on the alternator. Should see 14+ volts at the higher RPM ------------- Keep it as original as YOU want it 1978 Mustang (modified) |
Posted By: 797nautiqe
Date Posted: December-01-2017 at 4:11pm
| Unfortunately its too cold here in NW Ohio to test the boat in the water any more this season. Shouldn't the voltage be closer to 14 at the gauge if nothing is on other than the ignition? I will test the voltage drop this spring when the ice melts. I'm just trying to get a good idea what is going on. I've never had any issues with the batteries going dead yet. So I'm assuming its charging them to some extent. |
Posted By: 797nautiqe
Date Posted: December-01-2017 at 4:14pm
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Posted By: 797nautiqe
Date Posted: December-01-2017 at 4:22pm
 
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Posted By: Gary S
Date Posted: December-01-2017 at 5:14pm
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With out measuring with an accurate test meter it's all conjecture. Maybe your gauge is on it's way out and is reading low. Maybe it's off and over charging and thats why the batteries never run out. Won't know until you test it. ------------- http://www.correctcraftfan.com/diaries/details.asp?ID=1711&sort=&pagenum=1&yrstart=1966&yrend=1970" rel="nofollow - 69 Mustang HM SS 95 Nautique Super Sport |
Posted By: 797nautiqe
Date Posted: December-01-2017 at 5:18pm
| I understand Im just trying to get an idea where to start and what to look for. |
Posted By: Dreaming
Date Posted: December-01-2017 at 5:30pm
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you could run on the hose if you wanted to test, but I agree with Gary, start at the battery. check your full charge voltage- should be between 12V and 13v. Then with the engine running, the alternator should be putting out ~ 14.4v. less than 13v out of the alternator won't charge the boat, and more than 14.8 will be cooking the battery. If that checks out, then your gauge is suspect. If not, pull the alternator and start with a bench test. That will give you the base line of a healthy system. |
Posted By: KENO
Date Posted: December-01-2017 at 6:38pm
| In the first post in this thread he mentions already having the alternator checked and it tested good |
Posted By: gt40KS
Date Posted: December-03-2017 at 10:21pm
Then again, was it checked at Auto Zone?  Seriously though, I recently had my truck alt checked at O'reilly's and they said it was "good". My programmer confirmed the voltage was somewhat low, similar to yours. Didn't seem to charging well and the voltage would drop significantly whenever I turned on the compressor or fuel pump, again similar to your situation. Finally just spent the bucks for a new alternator and wouldn't you know the voltage is up to 13.5 - 13.85 and only drops about a quarter volt with BOTH accessories turned on. I'm not saying replace the alt and hope for the best, just don't discount that possibility, as I did for several weeks, just because a guy behind the counter said it was "good". Other thoughts may be battery or connection corrosion and faulty or weak ground that could be causing the low and dropping voltage. Not convinced that an undersized power cable would necessarily cause a voltage drop while using your ballast pump(s) - that would more be indicative of a failing pump motor, IMO, which is certainly possible. Also, don't rely on the dash analog needle gauge as they are notoriously inaccurate. You can pick up an inexpensive yet reliable multi-meter from any home improvement store like Lowe's, HD or Menard's. Don't go to an auto parts store - expensive for what you get and a lot of times not the best quality. They are an invaluable tool to have with boats, especially as they age.  ------------- JCCI 1995 Ski Nautique GT40 |
KENO wrote:Posted By: 797nautiqe
Date Posted: December-04-2017 at 10:11am
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I had the alternator checked at our local NAPA shop. I have a good fluke meter to test with. All the battery connections are in good shape and clean. All the battery cables are 1/o so im pretty sure they are big enough. I appreciate all the advice. The voltage is always low according to the gauge even with nothing running other than the engine. I know it will drop when accessories are used. Thanks again for all the suggestions |
Posted By: 8122pbrainard
Date Posted: December-04-2017 at 10:27am
Low per the dash gauge? What's the VOM telling you? Check you wire size up to the dash against the amp load..   ------------- /diaries/details.asp?ID=1622" rel="nofollow - 54 Atom /diaries/details.asp?ID=2179" rel="nofollow - 77 Tique 64 X55 Dunphy Keep it original, Pete < |
Posted By: KENO
Date Posted: December-04-2017 at 10:34am
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I guess if it was me, as a starting point I'd check the voltage right at the battery with the engine running and see what you have there. Like Dreaming and gt40KS said, you should have around 13.5 to 14 there. If you don't have that, then it would seem to be the alternator. If you have normal voltage at the battery when running (13.5 to 14 or so) check at the dash with your fluke and compare it to your voltmeter to see if the voltmeter is lying to you or if it agrees with the fluke. You could check right on the terminals to the installed voltage gauge. |
Posted By: SNobsessed
Date Posted: December-04-2017 at 10:07pm
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Just to be clear, all volt checks should use engine or battery as ground. ------------- “Beer is proof that God loves us and wants us to be happy.” Ben Franklin |
Posted By: NealXu
Date Posted: December-07-2017 at 2:23pm
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Hi....i am a new user here. As per my knowledge the wiring isn't up to the task of supplying all of the accessory pieces with power at one time.You'll need to run voltage drop tests on the entire system starting at the engine/alternator and working your way forward then to the accessories pulling the amperage. https://www.7pcb.com/blog/blind-buried-boards.php" rel="nofollow - buried vias pcb |