# 1999 90 Hp Mercury Wires Melted



## gbearden (Oct 19, 2007)

Last Year I had problems with my starter solenoid and was in the bay. In order to start the motor I had to Bounce the positive terminal on the battery so that the starter would not keep running. After that I noticed some "burnt" wire protectors around the wires that go to the power pack. Never did anything about it.







Today I got the boat out to use it (a year later after doing the repair to the starter solenoid) and noticed that the same wire protectors that looked burnt had completely melted in places. 



1. Was wondering if this was caused by weak placed in the wear that eventually wear out in places and created spark; 



2. and what I needed to do to correct the problem correctly. 







Thats guys for your expertise.


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## DOUBLE "D" & LV (Oct 2, 2007)

Do you by chance have a pic of those wires? Bouncing the battery terminal causes spikes in the system that can cause bad things to happen. If you have pics, it would help to see which wires are melted.


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## gbearden (Oct 19, 2007)

I will post pics of the wires as soon as possible. It seems the main wire that was the hottest was the red wire and the yellow wire (positive terminal I assume). 



I cut all the melted plastic away and taped up the wires with electrical tape and decided to use it anyway since I was already on my way out. The motor ran perfect all night, I periodically checked everything to be sure. I ran the motor for 7 hours straight with no problems. 



I do not want to leave it like this though. How tough would it be to replace the wires that are lacking the insulation. I would like to eliminate the problem before more problems arise.







Thanks for the help


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## DOUBLE "D" & LV (Oct 2, 2007)

Hmmmmmm. Yellow and red..... if it is solid yellow and not a yellow with a red tracer, then you are talking about your charging system. If those were melted, it means that there was a lot of amperage running through those wires. This is what can happen when floating the battery wires, or having loose connections while the engine is running causing spikes. It probably took out the regulator. With the wires in that condition, I would recommend a stator and regulator. We'll see what it is after the pic.s though.


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## gbearden (Oct 19, 2007)

Thanks for the replies. I have decided not to get a new stator and regulator because the regulator would run me atleast $150 and the stator $201 and that is doing the work myself. 



I am considering changing out the wiring harness to eliminate splicing the wires and reconnecting. 



My question is would this be overkill to purchase a new harness rather than just repairing the wires with new connectors? If at all possible I would like to repair it for as less as possible since it is working and running fine. I dont want any more costly repairs though, because I think I have avoided some serious damage twice already and the third time may do me in. I just want to fix it right.


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## outbrdwrench (Apr 8, 2009)

You say it is working properly. Are you sure it is charging the battery? If not &you want to fix it right, you should listen to the advice given by Davlor marine concerning the regulator! you could however save some money by testing the stator (there is a chance it is o.k.). If it is charging properly thenPerhaps you can repair the part of the harness that is damaged. But <U>make sure</U> you check<U>all</U>connections thouroughly! Especially the grounds. Excess amperagegenerated by the stator is shunted to ground through the regulator. Good Luck to you!


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## TimW Texas (May 20, 2009)

TrueI don't know about the newer Mercury some of the older ones had a rectifer on them that was the brain for the charging system I have seen them burn or melt wires from failure my 2 cents They have costed me around 30.00


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## outbrdwrench (Apr 8, 2009)

The rectifier on this model is built in to the regulator, it's function is to convert AC current to DC current.


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## gbearden (Oct 19, 2007)

As an Update; I had used the boat for seven hours on the water. This was at night and so my running/anchor lights were on the whole time. I also have two spotlights that I had running most of the time as well. I feel confident that if the battery was not charging then The amount of lights I was using would have drained the battery fast; certainly by the end of the night. 



I guess I got lucky not once but twice and didnt fry anything. My mistake can be a lesson learned. It all started with the starter solenoid, simple $30-$40 part could have cost me $300+.



Luckily all I will do is repair part of the wiring harness (just replace the connectors) and consider myself lucky. Next time I will either take the time to make sure I fixed the initial problem correctly or spend the money and take it to someone. 

:banghead


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## inshorecatch (Oct 1, 2007)

glad no one was hurt and the problem is fixed. If you dont mind me saying David is the man. :clap


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## DOUBLE "D" & LV (Oct 2, 2007)

Still didn't get pics.


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## outbrdwrench (Apr 8, 2009)

Yeah sounds like it is charging, but you need to make sure it's not overcharging! I've just never seen the charging wires melt & there be no damage to at least the rectifier,then again I am still learning everyday. Do this by measuring your battery voltage before you crank motor,should be about 12V. Crank motor & measure it at idle, should be 13-14V, then throttle only & bring rpms to about 2000-2500. If it goes over 15-16V, replace that reg. ,( stator is good ), or you will be buying a battery soon. I hope I'm wrong, but do this test just to cross your T's & dot your I's. Good Luck to you!


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