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-   -   2007 FXDL voltage regulator testing (https://www.hdforums.com/forum/electrical-lighting-alarm/1239566-2007-fxdl-voltage-regulator-testing.html)

Diesel2 06-20-2018 05:45 PM

2007 FXDL voltage regulator testing
 
How to test voltage regulator.
l had the battery tested at 2 different places and it showed/tested good at both.

So I believe in my case the regulator is draining the battery when the bike seats say a week or more.
I have removed the regulator and now after 3 days the battery voltage has remained at 12.86 volts.
Checking voltage every day at 24 hrs apart
I did some tests on the regulator that I have seen on Utube for a 3 phase system, but I am not sure on my testing unfortunately.
If the battery voltage remains at the 12.86 say nexk Wednesday which will be some 9 days and the bike starts then I would assume that would prove the battery drain is the voltage regulator as so far voltage remaining at the 12.86
If for sure the regulator then my choice for replacement will be the Cycle Electric regulator as I believe to be the best unit, made in your USA.
The OEM who knows.
It most likely up here is more costly then the OEM.
OEM 250. 00 and cycle electric 350.00 I believe.
Any help or advice most appreciated.

Zanthamos 06-21-2018 02:37 PM

Voltage regulator needs to be installed on the bike as it cannot be tested without a good ground. If you are having a paracitic battery drain through the V/R then you will likely have one of the pins on the output side show continuity to ground (this may not be a dead short (0 ohm) but this could be a slight short (1M ohm) the only acceptable answer is OL or infinity symbol depending upon your meter brand). See the charging system stickies for further information and get a Factory Service Manual as this is all covered in there as well.

Diesel2 06-30-2018 02:21 PM

Tested voltage regulator at the 3 prongs and got some 11+ volts at all 3.
So this means VR faulty and time for a new VR.
The diodes faulty and allowing voltage to back feed?
Is this correct and VR time to replace.
With VR unhooked battery voltage after some ten day measures at 12.76 volts.
Thank-you for everyone's help.

bustert 07-01-2018 08:16 AM

well, if you make a pigtail, most auto parts shops have alternator/regulator test stand. they just cannot connect to the hd reg socket. the machine supplies ac to reg and the reg is on a load bank that they can vary.
http://blog.jpcycles.com/step-by-ste...arging-system/

from j&p cycle tech dept.

Diesel2 07-04-2018 05:24 AM

Why can't you bench test a voltage regulator. I see it on you tube them testing 3 phase.
I tested with it on the bike as I stated before.
I unplugged the VR to stator, the 3 prongs and tested some 11 volts on the VR prong.
Now as I have asked, is that not a feed back from the battery which it should not do, which indicates the diodes are not stopping the back feed, although all 3 prongs showing a feed back.
There should be none from any of the 3 I would think.
I had the VR removed for 15 days.
Last night reinstalled it and the battery voltage was at 12.76 Volts.
Put main fuse back in and bike started wright up.
Before leaving the VR in and the bike sitting that long bike would not start and had to removed bat., and put on charge.
I no expert, but seems to me the bat staying charged for 15 days and the bike started wright up and the 11 volt feed back test from the VR would indicate that the VR is at fault.

nhrider1 07-04-2018 06:53 AM


Originally Posted by Diesel2 (Post 17475250)
Tested voltage regulator at the 3 prongs and got some 11+ volts at all 3.
So this means VR faulty and time for a new VR.
The diodes faulty and allowing voltage to back feed?
Is this correct and VR time to replace.
With VR unhooked battery voltage after some ten day measures at 12.76 volts.
Thank-you for everyone's help.

Sounds like a bad voltage regulator. I'd go ahead and replace it.

Zanthamos 07-04-2018 09:17 PM

You cannot bench test the VR because you cannot verify the ground connection. The only thing that you can test with it on the bench is the diodes to see if they are shorted to the case which would cause a paracitic drain on the battery.


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