Voltage drops when Nav lights are on
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=15435
Printed Date: November-18-2024 at 12:47am
Topic: Voltage drops when Nav lights are on
Posted By: anthonylizardi
Subject: Voltage drops when Nav lights are on
Date Posted: September-28-2009 at 3:46pm
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For a while I have been noticing that when I first start the boat, after a week of storage, the voltage is really low 9-10V. Then it goes back to normal. Last night when I turned the nav light on the voltage droped from 12V to 11V and after a couple of minutes the breaker tripped. Do I have a short somewhere? Could it be something alternator? Like a regulator or something like that? Any ideas?
Thanks, Tony |
Replies:
Posted By: WakeSlayer
Date Posted: September-28-2009 at 6:00pm
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I would get a nice good additional ground run up to your dash. I have a similar problem on my SAN, I am going to fix this winter. ------------- Mike N 1968 Mustang |
Posted By: behindpropeller
Date Posted: September-28-2009 at 6:11pm
The breaker in the engine tripped or the one on the dash? ------------- |
anthonylizardi wrote:Posted By: anthonylizardi
Date Posted: September-28-2009 at 6:17pm
| The Navigation Lights breaker on the dash. |
Posted By: behindpropeller
Date Posted: September-28-2009 at 6:29pm
You are drawing more current than the breaker can handle then. Check your bow light to make sure the contacts are not corroded. Work your way back to the switch. Tim ------------- |
Posted By: 8122pbrainard
Date Posted: September-28-2009 at 7:09pm
Tony, Tims idea is a good one. Any extra resistance caused by bad connections will cause a voltage drop. Then, as voltage drops amperage goes up. But, don't forget Mikes suggestion of getting some heavier wire (both ground and supply) up to the dash. Undersize wire will also add to resistance. The undersize wire is also a known problem. Last, the cheap breakers used, do wear out and they won't hold the amps like they do when new. To really test what the nav lights are pulling, you should hook up the mutimeter in series with the circuit. Make sure you hook up the meter to the 20 amp scale. ------------- /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: behindpropeller
Date Posted: September-28-2009 at 7:15pm
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Pete-
What makes you think the breakers they used are cheap? I don't see any reason to replace the wire with larger wire unless you increase the amperage draw of the light. If you have a ground issue find the issue and correct it. Sometimes you can mask a potential future problem by not finding the actual problem. Fix the problem, don't be a parts changer. Tim ------------- |
Posted By: TRBenj
Date Posted: September-28-2009 at 7:28pm
He's talking about running a larger gauge power and ground wire from the engine to the dash. These are known to be undersized from the factory. Every boat Ive seen from this era suffers from a low voltage reading at the gauge when multiple accessories are on because of this. I agree with the need to inspect the nav light wiring to deduce why its popping the breaker. ------------- |
Posted By: anthonylizardi
Date Posted: September-28-2009 at 7:28pm
| I will start troubleshooting and see what is causing the draw. I have voltmeter and ampmeters. Thanks for the ideas. Now I have a starting point. |
Posted By: WakeSlayer
Date Posted: September-28-2009 at 8:24pm
I am willing to bet this corrects my problem, not masks them. Perfect Passes also have extremely small ground wires on them and draw down voltage. ------------- Mike N 1968 Mustang |
Posted By: 8122pbrainard
Date Posted: September-28-2009 at 8:56pm
Tim, I should have used a different term here! Less expensive would be better. One thing for sure is the breakers used are not what I would consider a high end thermal magnetics. They will go and need to be replaced. This is why I recommended using the mutimeter to check the actual draw.
Yes as others have mentioned, I was referring to the feed up to the dash. Sorry I wasn't more clear on that. This is a known problem with undersized wire and does cause voltage drops. ------------- /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: WakeSlayer
Date Posted: September-28-2009 at 10:22pm
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My friends 94SN has a nearly identical problem to mine, however his 99SAN does not.
------------- Mike N 1968 Mustang |
Posted By: kapla
Date Posted: September-29-2009 at 1:35pm
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mine also has this problem!!! I will try to correct it also... ------------- <a href="">1992 ski nautique |
Posted By: eric lavine
Date Posted: September-29-2009 at 1:50pm
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keep in mind, all electrical problems are 98% poor connections ------------- "the things you own will start to own you" |
Posted By: kapla
Date Posted: September-29-2009 at 2:07pm
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Oh my connection are Kaplastyle!!! so what is the correct tape to use to cover the connections? regular electrical tape is a no go.. ------------- <a href="">1992 ski nautique |
Posted By: anthonylizardi
Date Posted: September-29-2009 at 2:09pm
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Any gauge recomendation for the ground cable?
Just in case I need to change it. |
Posted By: TRBenj
Date Posted: September-29-2009 at 2:15pm
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I wouldnt go through the trouble of disassembling the harness and removing the original wire- thats a PITA. Just add another one. The original should be 10awg, I would add another one of the same size or a 8awg (Both 12V constant and ground). ------------- |
Posted By: WakeSlayer
Date Posted: September-29-2009 at 2:23pm
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I have 2awg running up to distribution blocks behind my kick panel. These are for my amplifiers. I have additional ports on those that I planned on using. Any reason not to? I have checked all my connections behind the dash pod, and all seemed fine. ------------- Mike N 1968 Mustang |
Posted By: 8122pbrainard
Date Posted: September-29-2009 at 2:51pm
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Seb,
A high grade insulated and tinned "sta-con" (crimp on connector) is fine but if not insulated then I'd use heat shrink on them. There are also some types that come with heat shrink on the connector themselves that are adhesive lined. When you apply heat, it will shrink and bond to the wire insulation. Tony, Besides the above, you want to use marine grade wire. It's fully tinned preventing the copper wire from corroding. I've seen plenty of green connections!!! As Tim mentioned, don't forget both the feed and the ground. Mike, 2ga.!! That's good for over 100 amps. Wow, must be some HD amps up there! Ether that or you plan on hooking up a welder to it! You're correct though - as long as you're pulling wire, it doesn't hurt to pull oversize. ------------- /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: TRBenj
Date Posted: September-29-2009 at 2:53pm
If the 2awg wire is either: a) large enough to handle the maximum combined current of all the loads youre proposing to attach to it (stereo + dash) or b) fused below its melting point (181 amps), preferably as close to the power source (battery) as possible then you can hook up to that source without a problem. Since the ignition breaker is usually rated at 20A, use that in your calculation. Do the same for the ground! ------------- |
Posted By: behindpropeller
Date Posted: September-29-2009 at 3:50pm
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If you are going to add amps and all of that crap:
Use one of your dash switches to run a relay. Then pull the power directly from the relay to your audio stuff. No reason to run from the battery to the engine and then back to the dash. Tim ------------- |
Posted By: WakeSlayer
Date Posted: September-29-2009 at 4:12pm
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If I recall correctly, I have a 50A fuse in line, just off the battery connection. My batteries are in the rear hatch, next to the engine. They 2AWG is run up the gunnel to my amplifiers through distribution blocks, both power and ground, on the kick panel. My original plan was simply to run a heavier ground off the distribution block, to the ignition breaker. Test that. Possibly also to the heater breaker or switch.
Failing this, I would improve the power cable also. Am I off base here? Should I just do both at the same time? ------------- Mike N 1968 Mustang |
Posted By: TRBenj
Date Posted: September-29-2009 at 5:06pm
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Mike, Id do both- no harm in that. You might want to consider changing out the 50A fuse though. That 2awg can carry up to 181A safely. A 75A or 100A would be plenty safe still. ------------- |
Posted By: 8122pbrainard
Date Posted: September-29-2009 at 5:06pm
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Mike,
I feel your set up is fine to the amps. If you ever have any issues with low voltage at the dash then you can certainly use the 2ga. ground and feed off your distribution block. Plenty of wire there!! Just keep in mind the proper fusing/breakers. No need to add any relays ether. Keep it simple. The only reason you would want a relay is if you have a high amp load (your amps) you want to turn on and off with the ignition switch. ------------- /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: TRBenj
Date Posted: September-29-2009 at 5:10pm
Thats assuming the source (battery) is closer to the loads (dash) than the engine, and there is a clean way to run the wires between them. Thats not always the case. The stock set up is one scenario- unless you like the way wires coming out of the battery box look. ------------- |
Posted By: behindpropeller
Date Posted: September-29-2009 at 5:15pm
If you want to do it correct you really need to go directly to the battery. Otherwise you can watch your gauges bounce to the bass  ------------- |
Posted By: TRBenj
Date Posted: September-29-2009 at 5:27pm
Youre still talking just about the stereo, not the dash loads. Not applicable in anyones setup here, I dont think! Also, while its always smart to keep your power runs as short as possible (between battery and amps), so long as you account for the voltage drop due to the longer cable run to the engine and fuse everything correctly, everything will behave just fine and it wont have any effect on the dash. No one is suggesting that anyone run a high powered stereo off the ignition breaker, by the way- thats just absurd. ------------- |
Posted By: 8122pbrainard
Date Posted: September-29-2009 at 5:36pm
I agree. We are talking about gauge problems and voltage drop here. If you see bouncing gauges, then we're back to the undersize wire!! No matter where the high power load is pulled from, it's still the same electrical system. IE: same engine, battery(s) and alternator. ------------- /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: WakeSlayer
Date Posted: September-29-2009 at 5:43pm
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My stereo gear, as it run now:
-non powered deck is run off the ignition breaker. Nearly no draw at all. -PDX amps are run directly off the battery thru dist. blocks. My deck has the amp trigger wire to turn those on. -I am going by memory on the fuse size at 50A. I will report back when I get to this project. I think I will be fine. ------------- Mike N 1968 Mustang |
Posted By: anthonylizardi
Date Posted: September-29-2009 at 6:22pm
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Only the voltage guage drop 1 volt upon switching the Nav lights. The rest is fine.
Talking about stereo. I am buying all the parts to install a 2 4ch amps. I bought a gel battery and I hope to buy one of those battery switches. Then I wanted to run all my stereo from one battery and leave the boat battery only for engine and lights. Is this a good strategy? Do you think the alternator can charge both? I am replacing my batteries cables with new ones. As a preventive maintenance. Also, they were closing a marine store so I got them at 50% off. I bought all they have left, about 20' feet. |