Does the RR work on the AC circuit?


8 replies to this topic
  • Superboar

Posted January 26, 2010 - 07:02 AM

#1

'Lots of discussion about blown headlights. My '03 WR450 is showing 22 volts AC at the headlight but 14.5 volts DC at the battery when the engine is reved. So the rectifier/regulator (RR) is working for the DC side. There is a wire spliced into AC headlight circuit that runs to the RR - electrically the RR is not BETWEEN the headlight and AC circuit. So, does this wire to the RR suck over voltage out of the AC circuit? Or not which blows out the bulb...

  • Apple

Posted January 27, 2010 - 09:30 AM

#2

Not sure about your question, but FYI there were a lot of probs with the 03-04 regulators, mine over voltaged the CDI and cooked it and that was not a cheap replacement. $450 plus for the new CDI and regulator. I heard there was a Yamaha tech bulletin out about the regulator problem for the 03 and 04.

  • PBDBLUE

Posted January 27, 2010 - 08:26 PM

#3

Not sure about your question, but FYI there were a lot of probs with the 03-04 regulators, mine over voltaged the CDI and cooked it and that was not a cheap replacement. $450 plus for the new CDI and regulator. I heard there was a Yamaha tech bulletin out about the regulator problem for the 03 and 04.


Really????? Never heard that one before. I've put over 10,000 miles on both my '03 & '04 WR's and never a hint of a problem. If it was a big problem you would think there would be a lot of threads here on TT about it. That aside to answer the OP's question yes the rectifier/regulator also regulates the AC circuit.

  • Apple

Posted January 27, 2010 - 10:53 PM

#4

Maybe it wasn`t a huge problem but it doesn`t cost anything to check your voltage, as opposed to just assuming things are OK.

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  • Superboar

Posted January 28, 2010 - 07:05 AM

#5

...yes the rectifier/regulator also regulates the AC circuit.


DC circuit
coil---RR----battery and other DC components

AC circuit
coil
|
|-------------RR
|
headlight/taillight

How does it do this if the RR is in parallel with the AC circuit?

  • PBDBLUE

Posted January 29, 2010 - 12:37 PM

#6

DC circuit
coil---RR----battery and other DC components

AC circuit
coil
|
|-------------RR
|
headlight/taillight

How does it do this if the RR is in parallel with the AC circuit?


It's what is called a shunt regulator. It pulls the excess voltage (well current actually) to ground. Almost all dirt bikes use this type of regulator on the AC circuit. Not particularly efficient but it works.

  • Superboar

Posted January 29, 2010 - 07:43 PM

#7

Shunt regulator....
OK, I see in the electrical specifications that it lists both DC regulator (14.1-14.9 V) and an AC regulator (13.0-14.0V). My voltage at the headlight is 22 VAC. So it's going to need a new regulator.

  • Navaho6

Posted January 30, 2010 - 07:09 AM

#8

Superboar:

Start the bike and rev it. Voltage at yellow wire should be 13.0 to 14.0 volts (set your multimeter to ACV-20). If out of spec, it's the rectifier/regulator.

One thing I learned today is that cheap multimeters are not accurate on resistance measurements. I borrowed a good one from a friend and rechecked the coil resitance. It was within spec. My meter was way off.

Same goes for AC voltage check. You need to have an ACV-20 setting on your tester. Lowest mine had was ACV-200 and the reading was off by 1.5 V (too low).

Edited by Navaho6, January 30, 2010 - 01:35 PM.


  • PBDBLUE

Posted January 31, 2010 - 06:48 PM

#9

Shunt regulator....
OK, I see in the electrical specifications that it lists both DC regulator (14.1-14.9 V) and an AC regulator (13.0-14.0V). My voltage at the headlight is 22 VAC. So it's going to need a new regulator.


Yep. It's a combined unit (AC & DC).




 
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