Mysterious melting alt connector..

[BA80]

Thanks Doug

[dbeardslee]

Looking at the kits again I think I've got the 2.8mm and 6.3. Unless I'm reading it wrong, the 2.3mm has the round connectors, while the 2.8 uses the spade type.

[3Phase]

I ordered some new plastic sleeves for the harness from Cycle Terminal, then the page told me that it's closed during July for remodeling and a sanity break. Oops....

They're about the only place that seems to have the round male pin and matching female barrel terminals for the OEM connectors like the handlebar switches and the stop/tail/turn lighting connector.

It's supposed to reopen tomorrow on August 1 but it may take a while to sort through all the junk ordered by the morons that missed the giant Closed sign in the windows.

[BA80]

Yeah, it wouldn't even let me see all of the page. I was just going to wait until tomorrow.

[skids]

From memory, I think the phases can generate as much as 20+ volts. I think that a bad connection arcs and makes a lot of heat. There are four things to look out for with these bikes: cam tensioner, transmission dogs/slots, the connection for the pick-ups that shorts out when it gets wet, and the connection to the alternator (subject of this thread).

[Loch]

Ba80

the connection is loose. the heat damage is the result of high resistance. clean the connector to bare metal clean the male side also crimp the female a little to tighten its fit. use dielectric grease on bare metal to prevent corrosion

[BA80]

the connection is loose. the heat damage is the result of high resistance. clean the connector to bare metal clean the male side also crimp the female a little to tighten its fit. use dielectric grease on bare metal to prevent corrosion

Replaced both male connectors and the entire regulator with the females already.

[XJOK2PLAY]

Is there any info about the ampacity rating of these connectors?
I searched here, found lots of discussion about everything else, but no factual specs on their ampacity rating.

Makes me wonder if possibly these are too light duty for the task?

Also, I found a lot of discussion in earlier threads about specs like "XS11 alternators will produce 20 amps @ 14.5 volts @ 5000 rpms", and such...
but none about the ampacity value of these connectors.

These alternators are 3 phase, AC design. It gets converted to 12 volts DC by the Regulator/Rectifier. Most here know this.

BUT, this system, I would think, should fall under the category of "continuous duty". This term is used frequently in the NEC to accurately apply ampacity values to wires that heavy loads are placed on for time periods of more than 2 hours. Typically, wires and connectors that are made for "continuous duty" applications are not factored at 100%. Instead, they are factored @ 125%, because of the extra heat build-up they incur.

Also, when wires are left individually, in free air, they have a higher ampacity rating compared to when current-carrying conductors are bundled or placed in a conduit. They will then share heat with each other, and have a lower ampacity value. So, imagine... not only are these bundled together in a harness, but are placed in a hot environment to boot... which also gets an ampacity value derate. I do realize though that the wires we're talking about here are high-heat, fibre cloth covered... which I'm sure Yamaha figured would be adequate. What they may NOT have taken into account was the need for a heavier connector, too.

Since these connectors seem to have a common failure rate, and they are carrying AC power, not DC, it makes me wonder if they're not too puny, ampacity-wise?

Think of it like this... If it's rated as a 20 amp connector, 125% would be 25 amps. Add additional derates, it could easily need to be a 30 amp rated connector to not melt down under periods of heavy charge that exceed 2 hours or more.

I may be wrong here, but after seeing Bohn's brand new connector, that LOOKS like the original connector not only melt to a crisp BUT burned one of the 3 white alt wires out of that connector, too... well... one has to question the ampacity rating of the connectors, I think. Especially since yours has melted again, too Greg.

Bohn did say that his had been showing full charge for a long period of time just before it suddenly started showing 10 volts on his guage instead of 14.5 volts like it had been reading. Makes me think his reg-rec allowed the system to charge wide open, for more than 2 hours, and the connectors are not up to the task of handling that much ampacity for that long.

JAT.

[BA80]

I think it's due to the age of the connections Bob. Like old wiring in a house the connections will deteriorate over time due to elemental exposure and need repair.

When they were new they were fine but like you and I, time and exposure to the elements of time and nature make us less and less proficient.

[XJOK2PLAY]

Maybe true...
But these are new connectors that are melting, too... not just old ones.

Old ones melt first, then are replaced, then they also melt.

I see a trend... and that has led to my question.

[dbeardslee]

I found a reference to 6.3mm connectors that claims their max amperage is 15. I found it on the internet, so it must be true. Amp capacity of spade connectors

[3Phase]

I found a reference to 6.3mm connectors that claims their max amperage is 15. I found it on the internet, so it must be true. Amp capacity of spade connectors

Right... maybe 15A intermittent but not continuous, it's more like electrical outlet ratings. That link also says a Yellow crimp connector is rated at 48A.

I quit fighting that pesky Stator/Harness connector and got rid of it:




The barrier strip is mounted to the battery box using a nylon screw through a hole drilled in the original rubber plug.




An improvised insulator shield locks in freshness and flavor while it keeps things from shorting out the stator wires.




It's been a few years since I got rid of the connector and it's given me no problems. I'm rebuilding the harness on my '80G so I'm replacing the partially baked OEM 14 gauge stator White wires with fresh 12 gauge wires but the barrier strip is staying and so are the ring terminals. I'll probably keep the plastic coffee lid too.

.

[XJOK2PLAY]

Awesome, Scott!
What's that old saying...?
Necessity's the mother of all invention...

Cool!

[3Phase]

Yeah, it was pretty much necessity. The old connector toasted for the second time almost exactly like Greg's and Bohn's and everyones' connectors. I tried to remove the spade terminals but it broke so I could either replace it and watch it burn up again or change the game a little.

The steel high-temp wires and insulation from the stator to the harness are in great shape -- good job Yamaha/Hitachi. The copper in the harness wires from the stator connection up to the rectifier is an entirely different story, it's darkened and getting brittle in places and the resins in the plastic insulation are not really 'plastic' any more, they're closer to casting resins for making click-clacks.

.