Topic: 'flat part' on starter... oops, maybe it's the charging system!

[tonycb650]

set meter to dc volts, and put one lead on each battery terminal at the same time.

[martino1972]

oh,sorry,...oke...
hook up your battery like its supossed to be hooked up..
now put the multimeter on dcv(dc volts) and put one lead on the positve terminal of the battery and the otherone on the negative..
now read the voltage at a few different rpm's
idle,2500,5000 rpm
at idle it should read somewhat like 12.1/12.5 at 2500 around 12.5/12.7 and at 5000 more like 12.8/13.4

this will tell ya if she is charging or not by looking at the voltage..
a more complex method is possible by reading the amps,but if your voltage is good,you can safely asume its charging like it should.....

[Pinhead]

If you were a little closer I'd let you use my clamp-on DC ammeter. However, IMHO, a voltage reading across the battery is just as informative.

[Frankenkit]

Sounds a lot like the test I did earlier where it read 15 at idle. 

Going to wait until tomorrow when my PIC can hold the leads while I rev to different RPMs.

[martino1972]

tommorow...
oh,the suspense.....now i won't be able to sleep tonight....

[tonycb650]

Tomorrow? you slacker! you said you had alligator clips for your probes, so now is the time to use them!

[Frankenkit]

ha.  Alright. But if I poof the meter, I'll be complaining at you! 

So how do I hook these alligator clips up to the battery terminals without popping myself in the process?

[martino1972]

its 12 volt dc....you wont feel a thing,trust me,no danger,you could hold a finger on each terminal of the battery and you dont feel it...

[martino1972]

just make sure the that the leads on your multimeter are plugged in correctly..
the black one in the com and the red one in vohm..
if you would plug the red one in the ma or the 20a plug,9and black in com of cource) then it will short out the battery when you prong them.

[Frankenkit]

Ok. Well, just double checking, I hook up my gator probes to the multimeter, set it to the highest setting on DCV, start it up, read voltage sitting, at idle (once I get it idling w/o choke?) then at the prescribed RPMs to see where the charging band is?  This may be a touch 'off' just because my highbeam bulb is out, though I don't know that that'll change that much...

I want to make sure I won't blow the meter, it's not mine, and I don't want to deal with drama b/c I broke someone else's toy... (it happens often enough as it is)

[martino1972]

dont put it on the highest dcv,just put it on 20 dcv,more accurate reading that way..
and put your headlight on low beam then...

[Pinhead]

IMO if the battery is at 15 volts I'll guarantee you it's charging. However, 15 volts is too high; you either have a bad regulator or a bad connection [the vref wire] to your regulator.

[martino1972]

ha.  Alright. But if I poof the meter, I'll be complaining at you! 

So how do I hook these alligator clips up to the battery terminals without popping myself in the process?

you only get popped if you are using real alligators for it,

[Frankenkit]

Found a '79 service manual online, it says to test the red/white to any yellow AC and it should read 5-40 ohms,  as should green and any yellow....

then resistance in reverse should be 2000 ohm min.

I need to leave to pick my PIC up from work pretty soon, so I think I might hang it up for tonight and pick this all up again tomorrow morning after I've had some sleep and coffee (both.)  At least I know my rotor's good.

[martino1972]

then resistance in reverse should be 2000 ohm min.

wow,your bike has reverse??   

[Frankenkit]

Where are you? You need swatted! 

[martino1972]

Where are you? You need swatted! 

  ....that almost sounds good....  

[Frankenkit]

 

Thank god someone in the world has a sense of humor! 

I'm waiting in Portland with a rolled up newspaper. I don't give out presents often, but beatings are free.

[martino1972]

make that a rolled up motorcycle magazine and you got a deal....

[Frankenkit]

LOL    Man, you are my new best friend. 

[martino1972]

LOL    Man, you are my new best friend. 

that's some good news....

[Frankenkit]

Been busy working on the gf's Savage, not much time to f* with my bike... and couldn't find the gator clips! Gruh.  Did a test according to the honda svc manual I found online to test my rectifier: testing the red and green leads from the R/R to the 3 yellow AC leads, also from the R/R. The manual says 'spec' is 5-40 ohms... I got consistent readings in the 300s.     Going to do the rpm test, but wondering if this information would supercede that information, given the results.

[martino1972]

explain me from what wire to what wire,and illl tripple check(on 2 cb650's)

[Frankenkit]

"Take apart both connectors to the R/R, the large one and the small one.  With the red probe on the red and white striped lead, place the black probe on any of the yellow AC leads from the other connector.  Repeat with the red probe on the green lead."

I listed Honda spec as 5-40 ohms in the regular direction, then if you reverse it, you should have 2000 ohms min. 

Seems like my resistance is WAY too high, then...

[martino1972]

oke,at first i was checking this at the wireharnass side,thinking,what the hell is she talking about...oh,duh!!!!! on the r/r side of cource..

i don't know if you have a diode symbol on your ohm scale,but thats what i used,it looks like  -I<-

with ohms set on 200 or 2k i couldnt read anything(both bikes) but on the diode setting it did the following:

red probe on red/white,black on any yellow= 0
black probe on red/white,red on any yellow=5.56 on all three

then i did the same thing but then with the green wire and the result where the same,but viceversa..

any of this make sence???