Oh no! a mystery elec. fault again!

[Zanzibar]

Honestly I dont think I can get an answer here because there are too many variables. But...

I have a 3 wire connector coming from the reg/rect. One wire was melted so I fixed it up and plugged it in. With the bike running, it began to overheat, so out it came.

Funny thing is, (using Haynes,Section 9.30) the charging rate was unchanged (still correct), and the battery is in excellent electrical condition. How can this be with only 2 of 3 wires working?

So I did a leakage test (all Haynes guided) and instead of 0.1 mA (max) I have 1.05 mA. Haynes says this means I have a short. I have disconnected in turn every connector there is, and there is no change,ie no short circuit I can find.

Why doesnt a fuse blow if there is a short?

Any thoughts? I'm no good on autoelectrics.

[BobA]

I'm not 100% sure here, cos I can't quite get my head around what and how you are testing.

Are the three wires you are testing all yellow?

I'm wondering if the short circuit you are describing is actually on the stator, which would mean that disconnecting wires and removing fuses would not clear it.

If it is the stator, you will need to get it out of the side casing and replace or get it rewound.



Bob

[jasonbc]

Honestly I dont think I can get an answer here because there are too many variables. But...

I have a 3 wire connector coming from the reg/rect. One wire was melted so I fixed it up and plugged it in. With the bike running, it began to overheat, so out it came.

Funny thing is, (using Haynes,Section 9.30) the charging rate was unchanged (still correct), and the battery is in excellent electrical condition. How can this be with only 2 of 3 wires working?

So I did a leakage test (all Haynes guided) and instead of 0.1 mA (max) I have 1.05 mA. Haynes says this means I have a short. I have disconnected in turn every connector there is, and there is no change,ie no short circuit I can find.

Why doesnt a fuse blow if there is a short?

Any thoughts? I'm no good on autoelectrics.

They are the 3 phase cables for the generator, seems like something is overloading that 1 particular phase which is why it burnt out, maybe crap connections, water, cable breaking down. I did have a regulator rectifier burn out on my firestorm that could explain it as that would they draw more amps to overcome resistance. The bike would run fine then suddenly die leave the rectifier unit cool down for 3/4hr and it would be ok again. Don't know if this is any help though. All the big honda Bikes use the same unit if you have a mate with a similar borrow his ans see if it's any different

[Zanzibar]

Thanks Boba and Jason - yes its not easy to describe. I jut followed Haynes really, tho' I have more tests to do.

I mentioned the leakage rate and how I got a higher reading than Haynes allowed. Well I tested another AT (same model), and got nearly exactly the same reading! Doesnt make sense.

I have yet to test the alternator wires individually, but will do ASAP.

I suppose I posted in despair really - tho' the bike runs perfectly well! Maybe I shouldnt test stuff! But now I'm worried it'll just stop, after Iread your post. The reg/rect burned out about 5000 miles ago at 65000miles, and was replaced.

I'm going to ask around for an auto electrician who can have a look. I'll try to get a free one first.

Thanks for posting. I'll keep at it....

[Zanzibar]

Maybe you could help me with this....

Haynes says (page 9.30)in order to test the alternator, "measure the resistance between each of the yellow wires" etc.

Where do I stick the multimeter probe?- one in the wire of course, but where does the other probe go?

It tells you to do other stuff, but this is the first thing.


And do I stick in the + or - probe into the wire?

I have the required values in a chart, but where to put the probe?

Ta!

[BobA]

Without the guide in front of me, I'd check as follows. Hopefully this equates to the values Haynes give.

Check each yellow to earth. (so red probe on a yellow, and black probe to bikes frame/earth) I'm guessing there should be no reading between any of the yellows and earth.

Check between each yellow. (so red probe on one yellow, black probe on another yellow. The resistance in any combination should be the same, again, I'm guessing 0.1 to 1.0 ohm)

If I'm wrong with the above, could someone correct me please.

It might be worth chatting to Kymmy if you get in a pickle, as she is an electrical whiz.


Good Luck


Bob

[StumpyFingers]

Without the guide in front of me, I'd check as follows. Hopefully this equates to the values Haynes give.

Check each yellow to earth. (so red probe on a yellow, and black probe to bikes frame/earth) I'm guessing there should be no reading between any of the yellows and earth.

Check between each yellow. (so red probe on one yellow, black probe on another yellow. The resistance in any combination should be the same, again, I'm guessing 0.1 to 1.0 ohm)

If I'm wrong with the above, could someone correct me please.

It might be worth chatting to Kymmy if you get in a pickle, as she is an electrical whiz.


Good Luck


Bob

That sound right to me.
The resistance between the yellow wires should all be the same .

[Jim Davis]

Right, do all alternator checks first. That wire overheating was a sign from above you got a problem. Do NOT keep on riding with it unplugged and hope for the best.

Heat happens when resistance is high, such as in a poor connection. Heat will always happen in the weakest part of an overloaded circuit.

There are lots of way to check your alternator but one way is to check the Amperage out. It should be in A/C between the yellow wires only. Your Haynes should give you the proper way to test this.

With electrical problems there are so many things that can throw you off. Use the symptoms to guide you. You have a wire get hot, now find out why and fix it. It isn't normal.

The alternator wires no doubt go into the reg/rect unit. This unit converts A/C to D/C and then sends it to the battery. When the battery is full it starts letting off power as heat through the fins on the heat sink.

Analysing the Voltage on your battery during and after startup are a very good way to test your charging system in general but they require a good battery to start with.

If you have a good battery that's fully charged, first discharge it some by leaving a headlight on for a couple minutes. Now after you start the bike the battery will need topping up and you should see that happen, then after the battery gets full the Voltage will drop down to normal. This test will tell you if everything is working as it should on your bike.

Like I said first deplete a bit of charge from the battery. Now hookup a Voltmeter to the battery. Observe and write down the Voltage of the battery.

Now keep the meter in place and start the engine. Note the Voltage should rise quickly to well over 14-14.5V. If it does not, something is wrong. Now keep the engine revving a bit, 2500 or so and hold it until you see the Voltage drop to 13.8-14V. This is when the battery is charged back up and the regulator is starting to bleed off power as heat.

Write down all your reading and observations and report back.

[Zanzibar]

Thanks all. Will do. And thanks for spelling out where to stick the probe. It may be obvious to many, but I wasnt at all sure.

However I did find at the back of Haynes, definitions of terms like "continuity" etc. That helped.

I always admired the auto electrician - it all seemed so logical - till you tried it yourself!

PS I can feel a new alternator coming along.

[Zanzibar]

Battery reading before putting the h/lamp on for 3 mins - 12.87
" ............ "..... after..... " ......... .......... " ............. - 11.94
".................. during running ................................. - 14.53
"............ "......... ".... revving at 3000 rpm................. - 14.51

All this was done with 2 of 3 alternator wires connected. I also tried it with 3 but all the wires began to warm up, so I disconnected the one which previously fried, and that was ok.

Alternator continuity (3 yellows to earth one by one)
0.0
0.0
0.0

Alternator resistance of 3 wires (between yellow wires, ie to each other)
0.1
0.1
0.1

I thought I'd try testing the reg/rect, but it was beyond me because the unit is one (IGNITECH) fitted in the Czech Rep . All the wires are black and I cant work out what the original colours were!The diagram attached is in Czech.

I dont know what to think.

Incidentally, for the info, I checked the price of a Honda alternator rotor with David Silver - £425! gasp Then with a Wemoto pattern part- £67. But I still dont know the cause of this problem, and it might not be the alt.