This appears to be the problem. How do I replace it, and where to get one from.

What would cause it to melt like that? Dont want to repair it for it to happen again.

Any help really appreciated.

 

Welcome to SVR Andy. Sorry to hear of your problem, but I'm sure someone here will jump in. Good luck.

 

Hello Andy, welcome to the forums.

I had the same problem with that connector. Although my problems were intermittent and I had some trouble finding the culprit.
From time to time, bike would crank but wouldn't start, tacho and speedo going bonkers, trip distance resetting etc...

Same terminal melted as on yours.

This is after replacing the connector

Here's the schematic for relay

I've used this connector from Aliexpress, seems to be ok quality - LINK ,you only need Female set. My advice, buy a few of them if you fuck up terminal crimping (ask me how i know).
You'll need some crimping tool, soldering iron, wires(different colors preferably), heat shrink tubing and electrical tape.

I've cut my wires just behind the connectors to leave as much of them sticking from the harness, then I extended them 10-15cm to make it easier to crimp the connector terminals.

One thing to note is that on Gen1, this connector originally uses only 3 terminals. But as you can see on your photo, on the relay side two terminals are basically one, split into two.
I've soldered two wires onto the original Red wire to populate both terminals. I think it's like this on Gen 2 and newer, and should make a better contact than single one.


The reason for melting is bad contact and I think it could be because of the missing yellow plastic piece. This one

Overtime, terminals corrode and without that piece to keep them snug it gets worse, until it heats the surrounding plastic enough to melt and lose contact altogether.

 

Thanks for the reply. Thought it may have been overcharging, but after managing to get a connection, checked the voltage and got a steady 14.38v from idle to 4000rpm.
Have managed to find a replacement plug and pins, has the yellow piece in it too. The melted plug only had a rubber seal around the outer.
If I can get the pin out, I may try it in the blank terminal hole to get me to work til the new turns up

 

As a matter of interest/learning what part does this lead and connector play in the electrical system?

 

It supplies current to the Starter relay when the starter button is depressed. If the the contacts become corroded it can cause striation of the contact surfaces. Like most electrical connectors the resistance increases because of this which causes them to heat and eventually melt. This can be accelerated by a faulty starter relay which can draw more current than the circuit is designed for and heating the surroundings including the connector plug.

The cleaning and servicing of electrical block connectors and electrical contacts is as important as any other routine maintenance for preventing these kinds of problems. This includes the mating face of the Starter motor and the corresponding engine block mating face which should both be clear of corrosion/paint and grease. Same with the positive HT cable @ the Starter motor and it's corresponding insulation washers on the pole-piece.


HTH

 

I think that's a question for RecoilRob.

 

This should help explain how it works.

 

It looks like it pretty much feeds power to the rest of the bike.