Author Topic: Voltage drops as Engine speed increases  (Read 5502 times)

Offline VW_NUT

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Re: Voltage drops as Engine speed increases
« Reply #15 on: August 14, 2008, 12:09:06 PM »
I will check.  It will do it though even if you are rolling.  Say you are coming up to a light and pull in the clutch while you brake bam it'll stall. 


Now if you restart it at the light give it a blip it will idle the rest of the light just fine....   :annoy: :annoy:

Offline SubieHo

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Re: Voltage drops as Engine speed increases
« Reply #16 on: August 15, 2008, 10:51:09 AM »
Ok fellas, I hooked things up and checked the RR and also went through the Electrosport flow chart.
I've also  copied the chart for specified values from section 6 of the service manual. 

My readings seem way off.  I had to switch the range on multimeter to the 2 M ohm range to get any reading other than infinite.  However, when I went through the Electrosport flow chart, I either stop at "Bad connection from the positive lead from the RR to the battery" or "Bad connection at from the negative lead of the RR to the battery." What am I doing wrong?

In the following charts, the red lead is connected to points in top row and the black lead to points in the first column.

Y=Yellow     R=Red     B/W=Black&White     a=infinite     


Specified Readings:
             
         
                      scale = x 1,000 ohms
       Y1   Y2   Y3   R   B/W
Y1      a   a   3.5   a
Y2   a      a   3.5   a
Y3   a      a      3.5   a
R    a   a   a       a
B/W  3.5     3.5    3.5          6   


                              2 M ohm Range
   Y1   Y2   Y3   R   B/W
Y1      a   a   a   0.991
Y2   a      a   a   1.013
Y3   a   a      a   0.981
R   1.038   1.001   1.004      1.575
B/W    a       a      a         a   


Electrosport Readings with bike running at idle:

Voltage between battery terminals: 13 V - 13.5V -- it goes up as the engine warms up to operating temp.
If I rev it up to 5K rpm, it goes down to around 12.9V - 13V and stays there as I rev beyond 5K rpm.   

If I assume that the voltage reading is fine and move from left to right in the flow chart, then all is ok because my voltage stays way below 14.8 V. If I take the 13V reading, assume that it's low and move down in the chart, then I get a reading of .23-.24 V at idle (above .2 V), indicating that I have a bad connection between the positive lead of RR and the battery.  To make things interesting, I brought the engine up to 5K rpm and saw that the reading   dipped down to .14 V.

To make things more interesting, I moved down in the flow chart and and got a reading of .38 V at the negative lead, and if I rev up to 5K rpm, the reading jumps up to .7 V, which is above .2 V and indicates a bad connection from the negative lead of the RR to the battery.

All the fuses checked out fine. 

Question:  Where do the + and - leads from the RR go after they enter the wiring harness?  Do I need to slice open the bundle and check the wires? 

Offline VW_NUT

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Re: Voltage drops as Engine speed increases
« Reply #17 on: August 25, 2008, 10:02:53 AM »
Just did the test you guys speak of above and I did have a problem between the battery post and the RR.  The wires go from the RR to the 25 amp fuse to the battery.  The connections to the fuse block and at the fuse were corroded.  Voltage is now 13.5-14v now & no more headlight flickering. 

Offline SubieHo

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Re: Voltage drops as Engine speed increases
« Reply #18 on: August 26, 2008, 12:30:07 PM »
Thanks for the tip.  I'll definitely recheck the connections at the fuse box.

My headlight doesn't flicker,  but the low beams did not come on a couple of times after I first turned on and started the bike.  When this happens, the high beams work fine, and neither ever flicker. I wondered if I had a loose connection that lost contact from vibration so I opened the headlight and checked all the connections.  It hasn't happened again in the past 300 miles or so.

The bulb did look a little burned, but it's been working so I haven't swapped in a new one.  I have almost 22K miles on my bike.  How long do these bulbs last and would a bad bulb fail intermittently like this?
« Last Edit: August 27, 2008, 12:49:48 AM by SubieHo »

Offline Red01

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Re: Voltage drops as Engine speed increases
« Reply #19 on: August 26, 2008, 02:52:19 PM »
It's pretty rare for a filament type bulb to fail intermittantly... and the couple of times I've seem it, the bulb actually had failed, but the when the filament broke, it didn't fall apart, like theu usually do, but would maintain connection through vibration. This would usually make it normally "off" and occasionally make contact and come back "on".  So I'm voting you had a poor connection.
Paul
2001 GSF1200S
(04/2001-03/2012)
2010 Concours 14ABS
(07/2010-current)