Battery fire with second battery

[ecarnri]

I have a 1997 Maxum 2000 SRL with two batteries and a battery switch (to toggle between battery 1, battery 2, both, off). This weekend, I replaced my bilge blower and had disconnected my batteries. When I completed the blower replacement, I re-installed both batteries and ensured that the connections were very tight, including the lids on the battery case. When attempted to start the engine, my first battery (new battery about a month old), it did not have enough charge to start the boat's engine and it turned over, but did not start. So, I switched the toggle over to battery 2 (5-year old battery), and when I tried to start the engine, the battery started to arc quickly on the neutral (black) wire lead that connects to the battery. I could not reach my hand back to turn off the power to that battery and it quickly escalated to a fire and melted the top of the battery and I put it out with the fire extinguisher (glad I had it mounted within reach just under the helm).

When I finally put the battery fire out, I then tried to turn the battery switch back to #1, and I did not get any ignition lights or beeps and it was totally dead.

In looking at the battery wires (both positive and neutral) I seem to have accidentally crimped them with the top of the battery case which is a hard plastic case when I synched down the battery lid. Another, possibility is that when I toggled the battery switch from #1 position to #2, it did not exactly position itself on #2 and could have been off the #2 position by a fraction of a turn.

Questions: 1) Could this cut in the lines have compromised the circuit and caused the arcing on the batter lead?
2) Cut the possibility that the battery toggle position just off the battery selection have caused an arc?
3) In trying to restart the boat with the original battery (#1) and I did not get any helm lights to come on. I checked all the fuses and none were out. So, is there an inline fuse that I need to check, or is there a suspected bad ground?
4) I have taken off the battery switch and there are no fuses underneath it. Should I replace the battery switch (or how do I test it to ensure that it is still functioning)?
5) Any other advise for someone might give me as to what to troubleshoot before I take it in for someone to diagnose?

Thanks in advance for advice,
Eric

[mmwjr]

Glad to hear you were able to control things before the entire boat caught fire.
First a month old battery should not be low unless you have been running it down with the engine off.
Are you sure you did not reverse the positive and ground wires on the second battery?

Have you checked the engine breaker (red button on top of engine) and the 90 amp fuse on the starter?

What engine do you have and do you have the wiring diagram for it?
A cut in the battery wire jacket will only cause a short if it is in contact with metal and would have caused the problem as soon as you created the short. I do not see how the battery switch would cause this.

You will need the wiring diagram and start verify power at the battery, then the breaker, ... until you find the issue.

[ecarnri]

Thanks for the reply Mike. Sorry for the long delay in getting back, my boat has been at my cabin and I am back for the long Thanksgiving weekend to troubleshoot it.

Yes, you were correct, I had reversed the polarity of one of the batteries (battery #2). So, when I switched over to the battery #2 and tried to start it, it started to arc. Now, I have used a volt meter and tested the continuity on battery switch and the black/neutral wire to check for a good ground and both are fine. I do have a wiring diagram and am about to check the 90amp fuse on the starter, but it is so cramped back there, I don't know how to check it. Any advice on how I can first locate the starter, and more importantly, check the fuse?

Also, my wiring diagram states that there is a circuit breaker between the starter and where the wire bundle comes together. Where is this located and is it accessible without taking out the engine?

Any advice is appreciated.
Eric

[mmwjr]

Ok let's start with the engine breaker, it's mounter on top of the engine next to the slave solenoid look for the red button on it and press it in to see if it tripped.

What engine do you have? If a V engine 4.3, 5.0, or 5.7 if may be easier to remove the starboard exhaust to get at the starter. The fuse is mounted on it. If blown it will look melted or using the volt meter set to measure resistance ( ohms) measure across it two copper tabs, if good it will measure zero ohms.

[ecarnri]

It is a 5.7L Mercruiser V8 EFI.

I confirmed the 90 amp fuse is blown as I removed it and tied wires together and was able to get power to the console at the helm. :-) However, when attempting to turn over the engine as a test, I hear the solenoid engage and "click" but now my starter does not turn over. So, my issue now is it seems either my starter is blown/fried, or my engine has seized up with the recent cold weather.

Is there a test I can do to determine if the starter is functioning, without the headache of trying to take it out?

Second, I need to start the engine so that I can get anti-freeze pulled in with the winterizer kit. If it is just the starter, can I manually start the engine or is the compression too high to turn it over by hand?

Final question, if it is only the starter, I have another really old 1975 Bayliner boat with a 3.0 Mercruiser that has a 4 year old starter in it. That boat is worthless and I was going to donate it/scrap of this year. Can I cannibalize the starter from that engine?

Thanks again in advance,
Eric

[Kevlar7r]

There is no way you can start it by hand, but you can put a wrench on the harmonic balancer bolt and turn the engine by hand to confirm it isn't seized. I usually use a socket on a breaker bar.



As far as using the other starter, I doubt it, but I'll let others pitch in on that.

As an alternative, you can short the 2 terminals on the back of the starter together with a screw driver. This will bypass the solenoid, and let you confirm if it is the starter or the solenoid. This will create a big spark, so be very careful and ensure you are well ventilated.

[Phillbo]

Originally Posted by ecarnri

I confirmed the 90 amp fuse is blown as I removed it and tied wires together and was able to get power to the console at the helm. :-) However, when attempting to turn over the engine as a test....

This does not sound like a good idea. You know you have an issue that is causing the fuse to blow.It's there to protect components at the helm. By removing it instead of replacing it you risk further damage when you try to start your engine.

[mmwjr]

Ok so the reserved battery blow the fuse.

As Kev stated try turning the engine with a socket on the crank pulley but first remove the spark plugs to eliminate fighting the engines compression. Also if water is in the cylinders it will come out when the plugs are removed. When doing this turn counterclockwise in case the engine is seized the worst you can do is loosen the bolt instead of risking breaking it off.

But first did you confirm the battery is good and fully charged. The click first tell me not enough amp to turn the engine if the battery was good and the engine seized you can easly smoke the starter litterl.

I doubt the 3.0 starter will have the torque for you engine also being an older engine the mount will be different.

As far as winterizing remove the drain plugs on the block and manifolds. Then remove the t-stat housing and pour the antifreeze in from there as well as the four hoses that are on the t-stat housing until it comes out the drains, then reinstall the drain and continue adding anti-freeze until filled at the hoses and t-stat on intake

I sent you a PM.