Melted Battery Terminal :confused:

[BigX]

OK I have never seen this happen I need help. <br /><br />I have a 1993 Mercruiser 5.0 LX engine in my Larson Bow rider. Today I got in the boat and turned the ignition over. The started turned but did not engage. I tried a second time and everything worked fine. I docked at the fill station and filled her up with fuel. When I restarted her the same thing happend on the first attempt. The second attempt the starter engaged but did not have enough juice to turn the engine over. I switched the ignition to off but the started kept cranking. After fooling with the switch for about 20 seconds I pulled the safety lanyard and it shut the starter down. When I opened the hatch I saw smoke coming from the battery box. I got the fire extinguisher and opened the battery box. <br /><br />Inside I found that the terminal with the positve lead connecting to the starter had melted through the top of the battery and into the acid. I got the battery off the boat and on the dock as fast as I could. <br /><br />Has anyone seen this happen before? Did something in the starter short out and draw to much current? Why didn't the ignition switch shut the starter off, but the safety switch did? I assume the starter is bad, and the battery deffinately needs to be replaced, but is there anouther problem elswere I need to look for? I am having the marina diagnose the electrical system before I replace any parts, but I want to make sure nothing is overlooked. <br /><br />Thanks for any help you can provide.

 

[Trent]

Re: Melted Battery Terminal

Kill switch did not do it (it only removes power to the ign circuit). You just thought it did! Starter solinoid is stuck or the ign. switch is bad. The only way to stop a runaway starter is to disconnect the starter or the battery. <br /><br />Time to replace the starter and or solinoid now and your battery.

 

[BigX]

Re: Melted Battery Terminal

OK, That makes sense, when the terminal melted through the battery it probably removed all power. But my next question is Why didn't the engine turn over? Did the shorted starter not have enough power to turn the engine fast enough? Or do you think there is a problem in the ignition system. I guess an ignition switch is easy enough to diagnose with a ohm meter.

 

[DJ]

Re: Melted Battery Terminal

BigX,<br /><br />There are two things that cause excess draw in an electrical system.<br /><br />1. A dead short.<br /><br />2. Excess resistance in a circuit.<br /><br />More than likely, two of your three components are now bad, switch and battery. and of course, the cable.<br /><br />When you put this back together, make sure the negative connection, at the engine block is clean and tight.

 

[kdmiller8251]

Re: Melted Battery Terminal

BigX: <br />I had the same thing happen to me except the starter did not stay engaged. The cable melted through the battery, this was due to a loose battery connection.<br /><br />Good luck sorry to hear of your troubles.<br /><br />Tallman

 

[akriverrat]

Re: Melted Battery Terminal

this is why we run bilge blower befor starting. some gas fumes could have made this much worse.

 

[Bondo]

Re: Melted Battery Terminal

I think a new battery,+ new starter,+ a cleaning of all eletrical connections will cure all your problems....<br />A weak starter(needed more power),+ a Bad battery conection(couldn't deliver it) was the root of your problems...