TOPIC:

An oscilloscope would tell a lot. It would identify if any shunting was happening. It would show if a phase was not working. It would show if the rotor was slipping (by frequency of the ripples).

Another big help would be a .1-ohm, 50-watt resistor. You could put that in place of a fuse and measure it's voltage to get an accurate measure of the current (meter's usually go up to 10 amps, the resistor would allow up to 20 amps).

A good test would be to measure the current out of the reg/rec with a battery versus the cap.

Alright.

I built my inline fuse with switch contraption over lunch at work (go some strange looks for sure). Went riding a sum total of 50 miles tonight.

When started, had a beautiful 14.6V at 4,500 rpm and again the slow degrade to voltage hell.

By 9 pm I was trying my switch/fuse on the highway. High brake light fuse turned off didn't effect the voltage cap I was getting at 13.2. On the running lamp fuse and on the headlamp fuse, the voltage raised to about 13.5 /13.6, probably just due to the reduced load.

At home, all fuses pulled, I could rev the engine with the discharged battery up to 14.4 at around 5,000 rpm for 10 secs.

Seriously, how can I go about this oscilloscope business. Can you get one cheap or rent one? I'm desperate to finish testing this damn bike.

dnpurdy wrote:

Seriously, how can I go about this oscilloscope business. Can you get one cheap or rent one? I'm desperate to finish testing this damn bike.

Where abouts are you located? I might be able to hook you up!

@hobodan

I'm in chicago, north side of the city. Actually, I was thinking about this while riding -- oscilliscope would be nice, but so would a small volt logger. Used on a 20V scale it could give a nice charging history ona ride. On a 200mV scale with a current shunt, it could provide a nice amperage plot.

@loudhvx

The oscilliscope would plot the waveform from the regulator, but it would help with finding a bad wire/connector, right? I'm fairly certain it's not shunting, because on last nights right, I halfway through I disconnected the sense wire with no change. Perhaps I need to tie it to ground rather than letting it float, but it shouldn't matter too much, right?

I feel like we have verified the generator/stator portion of the system. I actually feel we have verified the regulator/rectifier portion through the combinination of "all but main fuse pulled tests" and "running with cap" tests.

I will try the current on hot wire out of rectifier tonight with battery and with caps. I have a 40A/400A DC clamp around ammeter, so I assume that would be easier than the resistor.


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I was thinking this weekend of pulling all but main fuse, connecting headlight directly to battery with extra wires, connect second headlight to simulate load of running lamps, and connect high brake light directly to battery to allow brake signaling and then going for another long ride. If the battery charges in this setup, then it has to be chassis wiring and not charging components, yes?

Post edited by: dnpurdy, at: 2007/06/13 10:04

The amp meter test out of the reg/rec will show if you are losing power or if the bike is using extra power.

If the current goes down over time, then the alternator is losing power, or you are losing power through a heating connection or wire. If the current goes up, then the bike is using extra power.

If the current goes down over time, you have to do a voltage check at intervals down the path from reg/rec output wire to the battery in order to locate where the voltage is dropping. If it doesn't drop anywhere from the reg/rec to the battery, in other words,if the output from the reg/rec is at a low voltage, then you have to assume the alternator is the problem.

I only recommend the resistor/voltmeter test because the clamp-meter will be hard to read while riding.

I'm off work this week, so let me know if need a hand.
I'm trying to get some bikes ready for Mods Vs Rockers at Delilahs this Saturday.

Post edited by: loudhvx, at: 2007/06/13 10:49

I can use an inductive timing light to check for rotor slippage, right. If I set the crankshaft to TDC #1, and put a sharpee mark on the rotor at 12 noon top. I know my timing and advanced are in spec, so at idle, with light, I should see the line on rotor fixed at 10 degrees to the right of straight up and down. As I rev up to 4000, it should continue to move out to 40 degrees right of 12 on the rotor.

If the rotor is slipping, I'd see the line process around if the slipping is very slow, or just all over the place if the slipping is bad. Basically, if the line doesn't stay fixed at a fixed rpm, i know the rotor is slipping. That sound reasonable?

my gut feeling is the rotor is not slipping, if it was it would slip the most under the heavy load, like right after the bike starts and it is at full output, also if its moving that much you would see some type of wear marks on the shaft providing you have removed the bolt, I think its on a taper shaft.

May have to work this backwards, bypass everything on the bike hot wire the ignition, and add fuses back one at a time to see when it starts to fall off,

Haven't taken rotor off yet. Will tonight to look for wear marks and to retorque holding bolt.

Only problem with the start lean and mean and add in is how do i know when the added piece is just normal load and not extra load.

I guess with a fully charged battery idling at 2,000, I should be above break even with full load. Only main fuse in, I should be at 15.5V. Since above break even and battery fully charged, the voltage shouldn't drop as I add fuses, right? Because 2000 is above break even, I should be shunting heavy before I add any extra fuses in, and by the time I add the last one I should be right at the shunting limit, so voltage shouldn't drop???

I think it would be a matter of looking at what was added, if it starts to drop rapid, then look at the items the fuse is feeding, then you could do a process of elimination to see where the drop stops.

It still puzzles me that you dont see any fried wires or hot ones either, that keeps me looking at the sense wire, dont know maybe I am in love with brown wires today:kiss:

dnpurdy wrote:

I can use an inductive timing light to check for rotor slippage, right. If I set the crankshaft to TDC #1, and put a sharpee mark on the rotor at 12 noon top. I know my timing and advanced are in spec, so at idle, with light, I should see the line on rotor fixed at 10 degrees to the right of straight up and down. As I rev up to 4000, it should continue to move out to 40 degrees right of 12 on the rotor.

If the rotor is slipping, I'd see the line process around if the slipping is very slow, or just all over the place if the slipping is bad. Basically, if the line doesn't stay fixed at a fixed rpm, i know the rotor is slipping. That sound reasonable?

Yes, but you can't put load on the rotor and see it at the same time. The stator is what loads down the rotor. I just thought if you had an oscilloscope, it would be easy to check the signal for slippage.

Put the bike in gear and turn the rotor by hand. If the bike moves forward and falls on you, the rotor is probably not slipping. But really, if you can move the bike with the rotor, it's probably not slipping.

I agree with BSK, that I wouldn't expect the rotor to be slipping. But if it's easy to check, it's worth it.

you thinking move bike on ground or on center stand. I'll have to have the woman help kept it upright if on ground...

this thing is killing me, if the charging system is working as you have proved, and there is a "draw" then wires would be hot, melted, or other wise bad, you would see it. since it quits charging at some time while riding, something is telling the charging system not to charge, so this goes back to the sense wire, or to the wires going to the rec/reg or to the battery.
I am just trying to make it simple