My st4 has a goosed connector block between the altenator & rec/reg. (it's looks like it has previously had a replacement section of wiring since there are now two connector blocks about 150mm apart) So I'm looking to do "the soldered connection" " remove corroded conection failure mode" mod... question is does it matter which of the 3 yellow wires from the altenator to the rec/reg connect to the other side of the connection? Sorry if this seems a dumb question, my knowledge of electrics crashes and burns after red to red, black to black (make that brown to brown, blue to blue) I've checked the resistance between each yellow wire and they are fairly consistent and all resistances to earth are open circuit which I believe means the stator wiring is still ok? Any advice would be much appreciated!
I assume this is a three phase generator, in which case you've got three coils all in series, with the end lopped back to the beginning, in a ring. At each coil connection there is a wire coming off. Hence each wire to wire should have the same low resistance and open circuit to earth. Assuming there is nothing fancy with the rectifier circuit then all should be fine for an any wire connection. Can you not see which wire went where?
There is an aditional short section of 3 yellow wires with 3 pin block connectors either end. The rectifier end is the goosed connector block. I'm assuming that this short section is a previous attempt at a fix. So if the connectivity did matter I would either need to trust the previous attempt, (which since it's melted isn't a great confidence booster) or establish for myself the correct connectivity. But since it doesn't matter, which is intuitively what I expected, I can the soldering iron out and crack on!! Cheers for the replies
There should only be one connection between the alternator and R/R.These plugs,after time,get a bit of cack on the pins and so have an increase in resistence.This resistence builds up as heat,eventually enough to melt the plug.
This is a common ST4 problem. The cable that links the alternator to the reg/rect runs very close to the radiator so it gets hot, and is exposed to water/crap via the fairing vents; so it doesn't last long. Last time I checked our local Ducati dealer couldn't find the right part number on their computer. (on the original 916 the reg/rect was mounted next to the alternator so the two just plugged together without the link cable in between. It's a three phase generator - hence the three yellow output wires - but the output is converted from a/c to d/c by the reg/rect; so, to answer the original question, no it doesn't matter which way you connect the three yellow wires at each end. When my ST fried the link cable I made up a new one - with thicker wires, crimped and solder terminals, slightly longer to give better routing, and with much heavier heat-shrink covering. Because the three wires had shorted together when the cable failed, the reg/rect was fried too. I fitted an Electrex one along with the home-made cable and I haven't had any problems since...
