Alternator wires got hot!!

motoddrob

motoddrob

Hero member
Location
S/W Australia
Pulling the motor the other day I had trouble disconnecting the 6 pin plug that connects the Alt wires to the RR. Turned the block over to find that the casing had melted and fused together.

P9240520_zps8028f93f.jpg


What the fuck would have caused that :o :o
I put my meter across the battery terminals a couple of weeks back and the RR was pumping out 14.7v. The alt is a Kawa ZZR250 unit.
I plan to relocate the RR out of the battery/electrical box as I think it gets quite hot without air flow. The connector block isn't sitting on anything that would melt it like that.
The melted part is the wires from the alternator to the RR.
Any ideas why that would happen??
 
Common thing to happen Rob, just use a more heavy duty connector - a solid connection between the wires.

Marnix
 
motoddrob said:
What the fuck would have caused that :o :o

Any ideas why that would happen??
Click to expand...

Too much load for the connectors, ie, too much electrical resistance.  They may be too small in cross-sectional area or the interaction between the respective connectors may be marginal, giving a too small contact surface.  Putting it out in the breeze will certainly help, but you do need to keep an eye on it till you're certain it doesn't get any worse.  Could easily lead to a terminal melt-down... for the whole bike!

piet
 
Thanks Marnix, Piet,
What worries me is, that's how it's been for several years so why suddenly start melting now??? Only real change it's now in a warmer environment being in the enclosed box.
In hindsight I'd do the box differently if I was to do it again, already have ideas formulating in my brain :-\
I'll install a new connector block and new connections and keep an eye on it.
Also move the RR out of the box, been wanting to do it for awhile, now the motor is out I can get to a few niggly things that's been annoying me off while I'm at it!!
 
motoddrob said:
Thanks Marnix, Piet,
What worries me is, that's how it's been for several years so why suddenly start melting now??? Only real change it's now in a warmer environment being in the enclosed box.
In hindsight I'd do the box differently if I was to do it again, already have ideas formulating in my brain :-\
I'll install a new connector block and new connections and keep an eye on it.
Also move the RR out of the box, been wanting to do it for awhile, now the motor is out I can get to a few niggly things that's been annoying me off while I'm at it!!
Click to expand...

That would be it, Rob.

Just needs a few more degrees of heat for these things to get started.  It then heats up the entire enclosure, making things worse by the minute... maybe a few breather holes could channel enough air to cool things down a bit.

piet
 
Only real change it's now in a warmer environment being in the enclosed box.
Click to expand...

Bingo!  The RR will be dumping a large part of alternator output as heat once the battery has charged.  If you don't run with lights on, then that's a lot of heat...try holding a 150w lamp in your hand!!

And you've pulled the plug & socket apart a time or two so it's contact resistance will have increased....

> Piet beat me to it!!
 
Aside from a more robust connector, there's another step you can take to resolve this issue, and prevent others from popping up.  Try a product called DeOx-It.  It does an amazing job of cleaning electrical connectors with a simple squirt, and it leaves a bit of protective film as it evaporates. Here's what made me a believer.  For years the horns on my Mirage failed to make any sound whatsoever when I hit the button. Jumping them straight to the battery terminals reproduced a loud sound, but the button did nothing.  One day I squirted some DeOx-It directly on the button, not bothering to open the housing on the handlebar.  The horns have worked wonderfully ever since.  I had used DeOx-It for a number of years now, and electrical problems that can be traced to corrosion and/or oxidation are history on my bikes.
I buy the stuff at Radio Shack here in the US. 
 
All of the tips given should be done on a regular (annual) basis, more frequent in high humidity and dust. Ideally there would be no resistance between the connector pins and the pins would never drop any voltage and heat up. Once the resistance increases from corrosion and arcing the plating material gets taken off, when cleaned it starts to work again but then the process gets repeated until finally the contacts have to be replaced, or you have a melt down. Similar things also happen to the battery connectors, ground terminations, and switches. The most common plating used is tin and is by far the least to last. Even with the connectors mated there is motion due to the heat build up from the resistance of the pin and socket (no matter the material that it is plated with they all move) that will remove the plating material. Hence, the corrosion starts and keeps on going until something doesn't work. Using the correct size of contact, using better plating materials (silver and gold are the most common, with gold the preferred), and minimizing the splitting of the connector will help prolong the life. Or, in our world of motorcycles have spare contacts available and when you see any corrosion at all replace them. Same thing we do to battery terminals, and where the ground attaches it needs to be checked more often due to the high current loads placed on the bolts used to make the connection. Water is the biggest enemy and when added with salt from the air it is a recipe for failure. DC4 electrical compound helps with keeping the crud out but you still need to check the contacts for corrosion.

As Piet said, left alone it could (will) be a bad situation. In my nuke submarine world we call that critical meltdown  :o :o :o

Replace the connectors and contacts with the best, some DC4, and a little preventive maintenance you minimize the failure rate.

Clay
 
Cosi said:
Would you believe mine is fucked and so is Peters, same shitty connection, things you find out on a laverda rally
Click to expand...

At least I know it's not something wrong with my bike then. Those connectors seem pretty much the standard jobbies available, Know of a source for better quality units??
 
Cosi said:
Would you believe mine is fucked and so is Peters, same shitty connection, things you find out on a laverda rally
Click to expand...

Better you find out there Cosi than on a ride in the middle of BFE with no cell coverage. AMP makes CPC's (Circular Plastic Connectors) that are far superior to the molex style on the bike. Here's a link to look at

http://www.digikey.com/Web%20Export/Supplier%20Content/Tyco_8004/PDF/Tyco_CircularConnectors.pdf?redirected=1

There are a ton of them but you break it down by contacts needed, then ratings, and then you live with the peace of mind  :D

Oh forgot to mention you will need a set of crimpers for the contacts, and you want the free hanging  :o style.

Clay
 
You must log in or register to reply here.
Back
Top