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Jmatt15
04-12-2006, 12:15 PM
I recently bought a beautiful 98 Prostar 190 (Sammy Duval) with only 50 hours on it. We took it out on the lake for the first time about a month ago and it would not start. We jumped the battery and got it to work the rest of that afternoon. The next day we replaced the battery and it worked perfectly, so we thought that must have been the problem. However, the following week we were looking around the engine and noticed a burnt wire near the alternator. After taking it to the dealership, they said we needed a new wiring harness b/c it had burnt all the way down the wires. However, they are not sure what caused the wires to burn. Has anyone had this problem?? What could have caused the wires near the altenator to burn??

88 PS190
04-12-2006, 12:31 PM
sometimes you see burnt wires on cars that have been jumped improperly. that could also be the case here.

I had a mechanic tell me that cars shouldn't be jumped unless they already have a fair amount of juice. ie. if its dead flat don't jump it, but if it turns really slow its safe to.

I guess the initial load on the alternator can burn wires or kill the alternator.

Hunterb
04-12-2006, 12:33 PM
Sorry to hear that with a new boat an all. My experience has been that burnt wires are usually the result of an unintentional grounding. Usually the insulation gets rubbed off a 'hot' wire somehow, then the core touches a bolt head or something else on the block and 'presto' you have full battery flow through a wire that's way too small and it heats up and burns. You should be able to just replace the burnt wire, or wires if it was in a bundle. Depending on the wire that grounded it may have damaged your alternator so you should check that out as well.

I'm sure there are other things that can cause a wire to burn, but grounding is the most common.

Hope that helps.

Bruce

Leroy
04-12-2006, 01:18 PM
Not many hours on that baby!

I would want to know which wire was burnt (assume it is the current to the battery wire). Should be a logical explaination for the wire or you are likely to be doing this again. Could be because it was running max current due to dead battery and there was a faulty connector causing it to heat up.

Workin' 4 Toys
04-12-2006, 03:42 PM
Do you have a picture you could post? And when you say burnt. Do you mean the wire was exposed with no insulation, or was it chared?Any chance someone may have crossed the cables to the battery?

Jmatt15
04-12-2006, 04:47 PM
Thank you for your reply. I do not have a picture right now, b/c it has been at the dealership for 3 weeks (MC sent them the wrong wiring harness and we are waiting for the new one). The wire was exposed with no insulation and you could see on there where it had melted. We are 100% sure that we did not cross the cables; however, we are not sure if the previous owner did. The wierd part is that we got it checked out at the MC dealership in the city we bought it from before we brought it home. The mechanic there said everything was in mint condition and it cranked there on the first try. Then we put it in the water and the battery was completely flat, so we jumped it with a jump box and it started up....we had to do that about 3 times that day. We had that battery checked out and it was a bad battery, so we replaced the battery and everything worked great the next day. Then we noticed the wire sticking out a few days later. The wire was connected to a negative terminal on the back of the alternator and it was burnt from the alternator to the back of the engine. There was not a tripped breaker / popped fuse.

Workin' 4 Toys
04-12-2006, 08:42 PM
It will be interesting to see what they find.
I wonder if they had the alternator bracket issues back then. If you don't know what I am talking about, do a search on alternator on this site.

And you said there is a wire that goes from the back of the alternator to the back of the block, for what I wonder?

How many wires were burnt?

Leroy
04-12-2006, 08:49 PM
I'm with you WFT, everything JMatt posts makes me want to ask a bunch more questions....but if the dealer has it I'm sure it will be fixed. Do ask them what they think happened.



It will be interesting to see what they find.
I wonder if they had the alternator bracket issues back then. If you don't know what I am talking about, do a search on alternator on this site.

And you said there is a wire that goes from the back of the alternator to the back of the block, for what I wonder?

How many wires were burnt?

Workin' 4 Toys
04-12-2006, 08:52 PM
Ask them for your old harness back too.....Call them ahead of time and tell them you want it. I would like to know how much was burnt.

Jmatt15
04-12-2006, 09:43 PM
The only thing the dealer said that may have caused it was reverse polarity, but he wasn't even sure about that. Hopefully it has not effected the alternator. We are going to stop by the dealership tomorrow afternoon and see if they will let us have the old harness before they put the new in...If they do, we will post a couple pictures of it.

Workin' 4 Toys
04-13-2006, 10:41 AM
I have seen burnt wires before...:o .. But it might help you solve the problem (Sorry to think it) if it happens again. It is just a thought, not to mention I'd like to see it. I know you saw the one wire you mentioned, but you should look for more throughout the harness that might have overloaded a circuit PRE-FUSE...
I hope all is well with it.

Jmatt15
04-13-2006, 09:05 PM
They wouldn't let us get the old harness before they put the new one in. But, we did take another good look at it and about 3 feet of the wire was melted. Also melted was the outer coating of bundle cover and you could see where other wires had started to melt. We will definately post pictures of the harness when we get the boat back (hopefully next week!).

Jmatt15
04-20-2006, 04:34 PM
Got the boat back today! We will be posting pictures of the wiring harness this evening. They still are not sure what caused it.

Jmatt15
04-21-2006, 09:48 AM
Here are some pictures of the wires. Luckily the altenator was not damaged.

Leroy
04-21-2006, 10:20 AM
WOW, I'm guessing mouse or squirrel! :eek:

Workin' 4 Toys
04-21-2006, 10:27 AM
Got the boat back today! We will be posting pictures of the wiring harness this evening. They still are not sure what caused it.
Well thats interesting.
In the 3 pics, was that ALL that was burnt?

Jmatt15
04-21-2006, 10:51 AM
Yep. That seemed to be all that was burnt.

Workin' 4 Toys
04-21-2006, 12:32 PM
This exposed wire. Where did it connect to? And was it one of the wires from that connector shown?

Jmatt15
04-24-2006, 09:24 AM
It was one of the wires from the connector shown. It was the purple wire that connects into the back of the alternator. See attached....

Hunterb
04-24-2006, 02:37 PM
I believe that wire is called the 'field' wire and it is live when the key is on providing power to the alternator. The large orange wire is the output wire. I am staying with my theory that the purple wire grounded out and received full battery flow which will quickly burn off all the insulation. It looks like there is opportunity for the wire to rub against the motor mount or the block which are both great grounding surfaces. I don't think it will hurt the alternator in that case as the current will flow to ground rather than the alternator and, if it stays grounded, burn the wire right off.

You should be good to go with the new wire. Just make sure it's not rubbing on anything.

Good luck. I hope it all goes well.

Bruce

Workin' 4 Toys
04-24-2006, 11:46 PM
Do they use fusible links on boats?