Battery cable #$%!!!?

[mkino]

Took the boat out last week. Started up fine... stopped engine outside the harbor for lunch. Wouldn't start!!! The starter kind of turned but only for a split second... sort of a 'chunk' sound then nothing.

Boat is 1991 Sea Ray 2250 with Mercruiser 454 / Bravo I drive.

Is this corroded battery cable connector likely to be the cause? I checked the battery voltage, both batteries are over 13 volts (I keep them on a trickle charger). Both cables look like the one in the picture...

I am going to replace the cables of course, I am interested in opinions about whether the thumbscrew style is good, or the clamp style that is used on cars? Seems to me the clamp style would be better...

Thanks for your opinions, you have helped me in the past!

 

[airshot]

Re: Battery cable #$%!!!?

I would advise you to never use the thumbscrew type of connections, the auto type clamp are much better. It appears that the cables may be lacking some maintainence, those connections should be cleaned and greased at least once per year. Mine get done at the beginning of every season and checked during the season. I assume you are in the southern area if you are boating this time of year, full year boating season around saltwater is even worse where corrosion is concerned. Notice the rust on the connectors...not marine grade cables, also add some grease to prevent additional corrosion after replacing with new ones. Now would be a good time to check all your electrical connections, if the cables are corroded so are other connections.

Airshot

 

[wrench 3]

Re: Battery cable #$%!!!?

I have the wing nut type connections on the batteries for my 454 Magnum, and they work great. The automotive clamp type tend to get beat up if they are taken on and off every year. I've seen those cheap cables on a lot of boats and they tend to loose connection between the cable and the cable end. They can be replaced with a solder on brass end.
If you have a 12 volt test light, start by hooking it up from the ground on the starter case to the battery cable stud on the starter solenoid. If it doesn't stay lit when you attempt to crank the engine, move the light down the system until you find where you're loosing it. Eg. move the light from the stud to the cable end and then the end on the other end of the cable. Same with the ground, move from starter to engine block, to cable, etc.

 

[MarkSee]

Re: Battery cable #$%!!!?

View attachment 182862.. I am interested in opinions about whether the thumbscrew style is good, or the clamp style that is used on cars? Seems to me the clamp style would be better...Thanks for your opinions..

As you can see from the first couple or responses, folks use both with success.

Nothing saying you can't use both connectors depending on where the other end is going.

Big ol' cable going to the starter: use the clamp style.
Cables going to accessories or add-ons that might not be quite as important: use the wing nut.

Mark

 

[Bob_VT]

Re: Battery cable #$%!!!?

Cables corrode inside the casing and the resistance goes WAY up and robs you of power. You need to investigate the cable under the insulation........ it will corrode badly when old and neglected. The solution..... replace the cables.

Based on your picture ......it not only needs cleaning but a light coat of Vaseline or grease. The corrosion happens is both fresh and salt water conditions.

 

[Bondo]

Re: Battery cable #$%!!!?

View attachment 182862

Took the boat out last week. Started up fine... stopped engine outside the harbor for lunch. Wouldn't start!!! The starter kind of turned but only for a split second... sort of a 'chunk' sound then nothing.

Boat is 1991 Sea Ray 2250 with Mercruiser 454 / Bravo I drive.

Is this corroded battery cable connector likely to be the cause? I checked the battery voltage, both batteries are over 13 volts (I keep them on a trickle charger). Both cables look like the one in the picture...

I am going to replace the cables of course, I am interested in opinions about whether the thumbscrew style is good, or the clamp style that is used on cars? Seems to me the clamp style would be better...

Thanks for your opinions, you have helped me in the past!

Ayuh,.... Pull the Spark plugs 'n Try it,..... Sounds Hydro-locked to Me.....

'n yer cable end is rusty,.. should be clean shiny metal, 'n Greased...

 

[tpenfield]

Re: Battery cable #$%!!!?

So . . . what was the outcome? Did fiddling with the cables bring the starter back to life? Did you have to get towed back in?

Is the engine running now?

I used to have a Mercruiser 7.4L Bravo 1 . . . it did the same thing. I thought it was battery, then starter . . finally took the spark plugs out.

 

[tazrig]

Re: Battery cable #$%!!!?

As everybody else has said the cable needs some cleaning and greasing. If it's that rusty at the battery I'd check it out at the starter too.

It also looks like the water hose (lower left in photo) that goes to your circulating pump is missing a hose clamp and has backed most of the way off the housing. Don't want to loose that sucker!

 

[mkino]

Re: Battery cable #$%!!!?

Good eye on the hose, I am replacing the impeller and needed to move that hose...

No conclusion yet, although I did have to get towed in...

I am going to buy new cables, the one at the starter motor has no corrosion, so just the battery cables. Still haven't decided whether to do clamps or wingnuts.

Does anyone know whether the size is 5/16" or 3/8"? hard to tell with a measuring tape...

Thanks so much for your input!

 

[Bondo]

Re: Battery cable #$%!!!?

Good eye on the hose, I am replacing the impeller and needed to move that hose...

No conclusion yet, although I did have to get towed in...

I am going to buy new cables, the one at the starter motor has no corrosion, so just the battery cables. Still haven't decided whether to do clamps or wingnuts.

Does anyone know whether the size is 5/16" or 3/8"? hard to tell with a measuring tape...

Thanks so much for your input!

Ayuh,.... It's either 1 of each, or 2, 3/8"....

Pull the spark plugs, yer cylinders are Rustin'....

 

[mkino]

Re: Battery cable #$%!!!?

Bond-O, you think the rusted connectors are not the issue, but water somehow got into the cylinders?? How would that happen?

You got me nervous enough, I will pull them tomorrow, then just see if water shoots out when you turn it over?

 

[55evinrude]

Re: Battery cable #$%!!!?

Bond-O, you think the rusted connectors are not the issue, but water somehow got into the cylinders?? How would that happen?

You got me nervous enough, I will pull them tomorrow, then just see if water shoots out when you turn it over?

because your boat is a 91 and those manifolds are probably original and may be rotted therefore water going back into the cylinders hydro locking the motor when you goto start it. like bondo said pull the plugs and try cranking it. if no water is in there than re install them and start checking other stuff....

 

[tpenfield]

Re: Battery cable #$%!!!?

I had a 1991 boat/engine . . . cylinder head (port side) started rusting through around the valve guides . . . hydro-locked the engine . . . bent a few connecting rods . . . game over for that engine.

I originally thought it was a battery/electrical/starter problem. :facepalm: $6K lesson learned.

 

[artificialreef]

Re: Battery cable #$%!!!?

Before replacing the cable wouldnt just using an ohm meter tell you if the cable is good? Old cables will get brittle and funky inside the insulation but your meter should tell you whats going on. Not sure what a good reading would be, maybe some pro's here could chime in. I am thinking a couple (2) ohms maybe. Make that rusted end "bright and tight" with sand paper. I have read some people spuuge it with dialectric grease though i have never used it.

 

[NHGuy]

Re: Battery cable #$%!!!?

Thunk is hydro lock. Been there, done that. If it's not I'd be very surprised.

 

[bruceb58]

Re: Battery cable #$%!!!?

Before replacing the cable wouldnt just using an ohm meter tell you if the cable is good? Old cables will get brittle and funky inside the insulation but your meter should tell you whats going on. Not sure what a good reading would be, maybe some pro's here could chime in. I am thinking a couple (2) ohms maybe. Make that rusted end "bright and tight" with sand paper. I have read some people spuuge it with dialectric grease though i have never used it.

Measuring resistance with a meter is pretty much useless because tenths of ohms are the difference between a good connection and a bad one. For example, 100A across a 0.1 ohm resistance would be a 10V drop. Best way to measure if a connection is good is to measure the voltage drop between the battery post and the cable lug while cranking.

The wingnuts should be removed and replaced with locking insert nuts.

 

[dubs283]

Re: Battery cable #$%!!!?

but water somehow got into the cylinders?? How would that happen?

number one cause is failed exhaust flappers

I will pull them tomorrow, then just see if water shoots out when you turn it over?

yes

 

[bruceb58]

Re: Battery cable #$%!!!?

number one cause is failed exhaust flappers

I would say number one reason is failed manifolds followed by dieseling.

Volvo doesn't even use exhaust flappers anymore. If it was the number one reason, they would.

 

[dubs283]

Re: Battery cable #$%!!!?

I would say number one reason is failed manifolds followed by dieseling

say what you want, i SEE it all the time

Volvo doesn't even use exhaust flappers anymore. If it was the number one reason, they would.

we're not talkin volvo here, mercruiser still uses exhaust flappers

 

[tazrig]

Re: Battery cable #$%!!!?

To mkino, (OP) So did you have a chance to pull the plugs yet and find out if the engine was hydro locked or not?