Voltage Drop Problem: battery, wiring or both - Page 2 - SailNet Community

   Search Sailnet:

 forums  store  


Quick Menu
Forums           
Articles          
Galleries        
Boat Reviews  
Classifieds     
Search SailNet 
Boat Search (new)

Shop the
SailNet Store
Anchor Locker
Boatbuilding & Repair
Charts
Clothing
Electrical
Electronics
Engine
Hatches and Portlights
Interior And Galley
Maintenance
Marine Electronics
Navigation
Other Items
Plumbing and Pumps
Rigging
Safety
Sailing Hardware
Trailer & Watersports
Clearance Items

Advertise Here






Go Back   SailNet Community > On Board > Gear & Maintenance > Electrical Systems
 Not a Member? 
  #11  
Old 08-07-2014
hellosailor's Avatar
Senior Member
 
Join Date: Apr 2006
Posts: 10,900
Thanks: 2
Thanked 103 Times in 100 Posts
Rep Power: 10
hellosailor has a spectacular aura about hellosailor has a spectacular aura about
Re: Voltage Drop Problem: battery, wiring or both

If you take a known good battery, and jump it directly to the starter with short fat jumper cables, that will tell you if the problem is internal to the starter, or out in your wiring.

Divide and conquer.

If it still doesn't want to start, you drop the starter and start rebuilding the solenoid and/or starter motor, something you might DIY or drop at a shop.
Reply With Quote Quick reply to this message Share with Facebook
  #12  
Old 08-07-2014
Senior Member
 
Join Date: Feb 2008
Posts: 164
Thanks: 1
Thanked 0 Times in 0 Posts
Rep Power: 7
preservedkillick is on a distinguished road
Re: Voltage Drop Problem: battery, wiring or both

Quote:
Originally Posted by hellosailor View Post
If you take a known good battery, and jump it directly to the starter with short fat jumper cables, that will tell you if the problem is internal to the starter, or out in your wiring.
This sounds like a good idea, thanks!
__________________
Preserved Killick


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.

Seagrass
Boothbay Harbor, ME
Alberg 30:
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
Reply With Quote Quick reply to this message Share with Facebook
  #13  
Old 08-07-2014
mitiempo's Avatar
Senior Member
 
Join Date: Sep 2008
Location: Victoria B.C. Canada
Posts: 7,286
Thanks: 0
Thanked 79 Times in 70 Posts
Rep Power: 8
mitiempo will become famous soon enough mitiempo will become famous soon enough
Re: Voltage Drop Problem: battery, wiring or both

Quote:
Originally Posted by Vasco View Post
It's for the engine control panel wiring. Installing a relay between the panel wiring and the solenoid will boost the voltage and it'll start every time you push the button.
I disagree. The starter solenoid doesn't use much current. That is why there is a solenoid there to start with. If the voltage at the solenoid isn't as high as it should be there is a wiring problem to or from the panel, either gauge, connections corroded, or age of wire. Adding a relay (really another solenoid) will not solve the problem only mask it and add more connections at the same time.

Now if there are glow plugs and they are powered off the panel a relay does make sense as they do use a lot of current.
__________________
Brian
Living aboard in Victoria Harbour
Reply With Quote Quick reply to this message Share with Facebook
  #14  
Old 08-08-2014
Vasco's Avatar
Warm Weather Sailor
 
Join Date: Sep 2006
Location: Toronto
Posts: 1,004
Thanks: 0
Thanked 8 Times in 7 Posts
Rep Power: 9
Vasco is on a distinguished road
Re: Voltage Drop Problem: battery, wiring or both

Quote:
Originally Posted by mitiempo View Post
I disagree. The starter solenoid doesn't use much current. That is why there is a solenoid there to start with. If the voltage at the solenoid isn't as high as it should be there is a wiring problem to or from the panel, either gauge, connections corroded, or age of wire. Adding a relay (really another solenoid) will not solve the problem only mask it and add more connections at the same time.

Now if there are glow plugs and they are powered off the panel a relay does make sense as they do use a lot of current.
I agree the problem is from old wiring. But rather than change out the wiring harness it's much easier to install a relay. The relay does not mask the problem it fixes it without having to get a new harness. As I said in an earlier post you might try cleaning all the contacts first.

As for the relay in some newer Yanmar installations a relay is already installed.
__________________
Rick I
Toronto in summer, Bahamas in winter.

To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
Reply With Quote Quick reply to this message Share with Facebook
  #15  
Old 08-08-2014
just ducky
 
Join Date: Aug 2008
Location: NH
Posts: 966
Thanks: 4
Thanked 22 Times in 21 Posts
Rep Power: 7
Don0190 is on a distinguished road
Re: Voltage Drop Problem: battery, wiring or both

a relay only adds a couple of feet of wire

but if the problem is a bad connection from the switch to the solenoid in time the relay even wouldn't get power (still worth having the relay for times when starter battery voltage is at it's lower limit)
__________________
Don't blow air up my rear, be useful and blow it at the sails!
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
Reply With Quote Quick reply to this message Share with Facebook
  #16  
Old 08-08-2014
Senior Member
 
Join Date: Feb 2011
Location: San Francisco Bay area
Posts: 2,300
Thanks: 2
Thanked 45 Times in 45 Posts
Rep Power: 4
MarkSF is on a distinguished road
Re: Voltage Drop Problem: battery, wiring or both

I've spent quite a bit of time trouble-shooting an intermittent no-start problem, that only occured after the engine had been heat-soaked (ie, re-start an hour after shutdown). The solenoid went click, but the starter did not spin up.

There are many things that can go wrong.

1) You need a healthy voltage to activate the solenoid. This is down to the ignition switch and wiring.

2) You need a healthy voltage at the starter main terminals. This depends on the cabling, battery switch, and starter battery.

3) You need a healthy starter motor.

Firstly, you need to systematically measure the voltage drops in your system. The starter motor needs at least 9V, ideally 10. You need to measure the voltage at the starter terminals WHILE CRANKING.

For voltage drops, connect the meter between battery + and starter +. Then repeat for battery - and engine ground. Again, measure while cranking. Please note that the losses on + and - sides add up.

Good cabling and battery switch should give you a 1V drop or less. A good battery should hold up to 11V while cranking, leaving you a healthy 10V at the starter.

In my case pretty much everything was wrong. Poor battery cables, an ageing 1-2-both switch, weak battery, ageing ignition switch, poor quality wiring to the solenoid.

So I now have new 2/0 battery cables from Genuinedealz.com, a new ignition switch, new wiring to the solenoid, a new 1-2-both switch from Blue Sea Systems, and a new group 31 battery from US Battery. Very healthy voltage at the starter now.

But guess what? The intermittent start problem was still present. I replaced the starter motor, all is good so far. Will need 6 months of use before I declare it fixed!
__________________
1984 Bristol 31.1
Alameda, California, USA
Reply With Quote Quick reply to this message Share with Facebook
  #17  
Old 08-08-2014
Senior Member
 
Join Date: Feb 2011
Location: San Francisco Bay area
Posts: 2,300
Thanks: 2
Thanked 45 Times in 45 Posts
Rep Power: 4
MarkSF is on a distinguished road
Re: Voltage Drop Problem: battery, wiring or both

Quote:
Originally Posted by mitiempo View Post
I disagree. The starter solenoid doesn't use much current. That is why there is a solenoid there to start with. If the voltage at the solenoid isn't as high as it should be there is a wiring problem to or from the panel, either gauge, connections corroded, or age of wire. Adding a relay (really another solenoid) will not solve the problem only mask it and add more connections at the same time.

Now if there are glow plugs and they are powered off the panel a relay does make sense as they do use a lot of current.
I agree. The starter solenoid IS a relay. So you're adding a relay for a relay. Will that relay need a relay too?
__________________
1984 Bristol 31.1
Alameda, California, USA
Reply With Quote Quick reply to this message Share with Facebook
  #18  
Old 08-08-2014
Senior Member
 
Join Date: Feb 2011
Location: San Francisco Bay area
Posts: 2,300
Thanks: 2
Thanked 45 Times in 45 Posts
Rep Power: 4
MarkSF is on a distinguished road
Re: Voltage Drop Problem: battery, wiring or both

Quote:
Originally Posted by mitiempo View Post

Now if there are glow plugs and they are powered off the panel a relay does make sense as they do use a lot of current.
My Universal was wired so that the start button is only energised via the glow plug switch. The problem with that is, you have the glow plug current dropping the starter solenoid voltage!

I have rewired it so the two are separate.
__________________
1984 Bristol 31.1
Alameda, California, USA
Reply With Quote Quick reply to this message Share with Facebook
  #19  
Old 08-08-2014
travlineasy's Avatar
Morgan 33 O.I. Perryville
 
Join Date: Dec 2010
Location: Maryland
Posts: 2,633
Thanks: 3
Thanked 82 Times in 68 Posts
Rep Power: 5
travlineasy will become famous soon enough
Re: Voltage Drop Problem: battery, wiring or both

I strongly suspect the problem is with the starter, thus explaining the higher than normal voltage drop and battery load-down. Marine starters are not any different that an automobile starter. There's nothing to prevent corrosion causing moisture from getting inside, and in the damp environment of a boat's engine compartment, it doesn't take long for the process to begin. The only method I know to control that environment is to install a good ventilation system, which in my boat is a 72mm computer fan that runs pretty much constantly, but uses very little electricity. It draws just .04 amps, but it moves a lot of air at 12 CFM. Since that fan was installed, my engine room corrosion problems have ceased to exist. The fan cost me a whopping $7 from Amazon.com.

Good luck,

Gary
Reply With Quote Quick reply to this message Share with Facebook
  #20  
Old 08-08-2014
Senior Member
 
Join Date: Oct 2011
Location: Naniamo B.C.
Posts: 2,085
Thanks: 2
Thanked 37 Times in 37 Posts
Rep Power: 4
Capt Len is on a distinguished road
Re: Voltage Drop Problem: battery, wiring or both

Take an old solinoid apart to see that the two bolt ends that are the terminals are corroded. More important is the copper end of the moving part. When it pits up too bad it may or may not connect across the bolt ends and can be temp sensitive. (Click,click) If you turn it 90 degrees you can get some more life out of it .That's pretty haywire. but I've done it in the snow up a logging road.
Reply With Quote Quick reply to this message Share with Facebook
Reply

Quick Reply
Message:
Options

By choosing to post the reply above you agree to the rules you agreed to when joining Sailnet.
Click Here to view those rules.

Register Now

In order to be able to post messages on the SailNet Community forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.
Please note: After entering 3 characters a list of Usernames already in use will appear and the list will disappear once a valid Username is entered.
User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.
Password:
Confirm Password:
Email Address
Please enter a valid email address for yourself.
Email Address:

Log-in

Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.




Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools

 
Posting Rules
You may post new threads
You may post replies
You may post attachments
You may edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is On


Similar Threads
Thread Thread Starter Forum Replies Last Post
Voltage drop? utchuckd Electrical Systems 17 05-27-2014 12:37 PM
Huge Voltage Drain Problem - Ideas? JohnZion Electrical Systems 27 11-07-2013 11:13 PM
Measuring Battery Voltage ccriders Electrical Systems 6 11-13-2010 07:41 PM
Masthead lght voltage drop to zero under load Uberbigun Electrical Systems 2 05-26-2009 05:45 PM
Voltage Drop rayncyn51 Gear & Maintenance 6 03-17-2009 01:58 AM


All times are GMT -4. The time now is 10:46 AM.

Add to My Yahoo!         
Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2014, vBulletin Solutions, Inc.
SEO by vBSEO 3.6.1
(c) Marine.com LLC 2000-2012

The SailNet.com store is owned and operated by a company independent of the SailNet.com forum. You are now leaving the SailNet forum. Click OK to continue or Cancel to return to the SailNet forum.