Won't start - hot battery posts!

[ribblette]

I am trying to get my '88 2.3L omc ready for the season. When I turn the key, I get a click from the back and the battery wires move! Then there was a little bit of smoke coming from the battery posts. When I investigated closer, the battery posts were very hot! The negative post was hotter than the positive, but both were hot.

I have read Don S's electrical troubleshoot and plan to go through that, however I thought someone might have some input on why the connections are so hot?? Is it possible that my battery wires are no good? They look ok, no corrosion, but they are very old.

Also, thanks for a great forum. I have successfully done a lot of work on the boat by searching through old posts.

Lesley

 

[bruceb58]

Re: Won't start - hot battery posts!

You have a highly resistive connection there. The connection at the battery is either not tight enough or the cable inside the swedge to the connector is corroded. The reason one is hotter than the other is that the hotter one is a more resistive connection.

 

[ribblette]

Re: Won't start - hot battery posts!

Thanks for the fast response. So, step one should be replaced the old battery cables and terminals? I will pick some up this afternoon and try that.

 

[bruceb58]

Re: Won't start - hot battery posts!

So, step one should be replaced the old battery cables and terminals?

No..step one is to see if what you have is tight enough. You may be buying new cables but why not try the simple things first?

How is your battery cable attached to your battery? If it a large wing nut, ditch that and get a stainless steel hex nut.

 

[brunolund]

Re: Won't start - hot battery posts!

how about ensuring all your connection are CLEAN???

 

[brunolund]

Re: Won't start - hot battery posts!

and then tight.

 

[ribblette]

Re: Won't start - hot battery posts!

Ok, I have what seems like a dumb question. Here is what my battery connections are like:

4 Ga. Red attaches to the large positive post with a clamping battery terminal. The battery terminal is in pretty bad shape, however it worked last season. The bolt that clamps the terminal is rusty, and it has a wingnut. When I tighten that wingnut has much as possible, the terminal still jiggles on the post very slightly.

4 Ga. Black attaches to the small negative post. No clamping terminal on the wire. A wingnut screws onto the small post.

So, my dumb question is... should the ground/negative wire be attached to the large post?

 

[CharlieB]

Re: Won't start - hot battery posts!

ALL battery terminal, both ends of each cable, must be clean, bright and TIGHT.

NO MOVEMENT, any movement is a weakened connection.

Wing nuts can be fine IF TIGHTENED ADEQUATELY

Most peopple do not have the finger strength to adequately tighten wingnuts, replace them with a stainless steel nut that you can use a wrench to ensure that you get it tight.

 

[Maclin]

Re: Won't start - hot battery posts!

Your negative connection is probably ok where it is. But I do have a queestion, Does your battery have a large clamp-on post and a small studded post on each terminal? If not then your question about the negative post is scaring me a little.

I think your positive cable needs replacing. Read your own description of it.

I like to use the studded terminals and cables with just a lug on it, not those clampon type of terminals. Clean off everything with a wire brush before re-attaching. If you are replacing the positive cable leave the negative connections off until the positive one is attached at both ends.

 

[bruceb58]

Re: Won't start - hot battery posts!

Wing nuts can be fine IF TIGHTENED ADEQUATELY

Most peopple do not have the finger strength to adequately tighten wingnuts, replace them with a stainless steel nut that you can use a wrench to ensure that you get it tight.

This is important...ditch the wingnuts. Replace with a locking stainless steel nut.

 

[ribblette]

Re: Won't start - hot battery posts!

Thanks for all the advice, guys. It has been raining here all day, but when it stops, I will first try cleaning and tightening everything (with nuts, not wingnuts).

 

[ribblette]

Re: Won't start - hot battery posts!

Oh, and yes my battery has a large clamp-on post and a small threaded post on each terminal.

 

[Bondo]

Re: Won't start - hot battery posts!

Ayuh,.......

Don't forget the Other End of those wires,........ Both sides......

Remove, Sand, Clean,+ reinstall........

I smere a heathly coating for Grease on Mine,...... No Corrosion that way.......

 

[Fireman431]

Re: Won't start - hot battery posts!

One more thing to think about...if the terminals are getting hot and the connections still "wiggle", (s)he may have a bad cell in the battery and causing a short. The terminal getting hot softens the plastic casing and the connections, although tight, will actually wiggle in the plactic case. It may be a case of a bad battery. Easy enough to use a hydrometer to check the cells.

 

[marco_0521]

Re: Won't start - hot battery posts!

Lesley,

Can you confirm that the click you are getting comes from the starter solenoid? This would confirm what many have already told you, that you have bad connections or that the battery might be at fault. I would focus on both ends of the ground as a bad grounds have given me a fair share of starter clicks.

You mentioned that the battery posts get hot. Is it just the posts or are the wires also getting hotl (either one, the positive or the ground)? Heat is caused by high amperage, if the cables are also getting hot (even if not as hot as the posts), then consider that you might have a short circuit somewhere.

The movement of the wires is also another clue, since it could be due to some physical contact (can't think of one) or due to a magnetic field. Magnetic fields again are formed by high electrical currents. To eliminate the possibility of a short, make sure you have a working fuse in your circuit (don't jump it!!!).

Finally, another idea. If you clean the posts and still does not work, take the cables and inspect them for any cuts. If water went inside, you might have high levels of resistance due to corrosion. An objective way to measure this is to take them to Autozone and they can measure resistance for you and let you know if they are OK. The lower, the better. The specs for a #4 cable, is about 0.25 ohms per 1,000 feet. If you have a 10-foot cable, then you should have 0.0025 ohms (virtually nothing, a normal voltmeter will show 0).

Good luck!

 

[Lou C]

Re: Won't start - hot battery posts!

On a boat that age, (I have an 88 OMC Cobra too!) ditch the old cables. Mine were trashed and I tossed them 5 years ago when I put in my dual battery system. You can measure the old cables and go to a good marine shop or even West Marine have new cables made up to the right size, with clamp terminals on the battery end (like car batt clamps) and with terminal ends on the other end where the cables go to the starter and engine ground. If they are 4 gauge consider upsizing to 2 gauge, bigger gauge wire=less resistance. And make sure you use the good marine battery cables, not the auto stuff, it will not last. Make sure you clean the ground connection on the engine, and cover with grease. I did mine this way 5 years ago and even sitting in salt water they have been fine.
Finally you might want to check the terminals on the starter itself, they could be corroded too.

 

[newport dave]

Re: Won't start - hot battery posts!

Your engines frozen or hydrolocked.

 

[Don S]

Re: Won't start - hot battery posts!

When I turn the key, I get a click from the back and the battery wires move!

Yea, I think Dave has it nailed.
That click is probably closer to a solid CLUNK.

 

[JustJason]

Re: Won't start - hot battery posts!

pull all the plugs and try it.....

 

[bruceb58]

Re: Won't start - hot battery posts!

I think he needs to get his battery cables in a good state before jumping to the conclusion that the engine is seized or hydrolocked. It could possibly be that outcome but first thing first is getting a battery cable that wiggles on the post back to making a good connection.

To borrow Don's quote that the "crystal ball is out of order", we don't have enough info to make any good guesses here.