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Discussion Starter · #1 · (Edited)
Good day all, I'm having some electrical troubles with a 2000 model VT750 ACE. I have access to the factory service manual and have been going through the battery charging / troubleshooting flow chart to try and diagnose the problem. I have also been doing some reading through this forum to familiarize myself with how the electrical system is made up. This is my 1st motorcycle, so I am in the learning process right now. I'd like your opinions where applicable on the matter.

1) At idle, voltage rests at 11.xV - 12.xV and struggles to climb higher the more I rev the motor. When the battery runs flat, the bike cuts off.

2) I somehow blew the head light fuse while connecting a charger to the battery, while it was still connected to the bike. I left the headlight off and redid the voltage tests. I then got way over 15V when I idle up the motor! I automatically assumed the regulator / rectifier is bad at this point.

Bad Regulator - YouTube

3) Continuing through the manual, I decided to check the stator to make sure that is OK. At the 5 pin connector to the R/R, I wasn't getting any resistance between two of the 3 coils from the stator (measuring between the 3 yellow wires). 5 pin R/R connector seen at bottom of pic.



4) Page 16-9 in the manual makes mention of a charging line (3P connector). I finally figured out where that connector was and saw the terminals badly corroded. I measured the resistance between the 3 yellow wires on that 3P connector and got less than 0.5Ω each. If I followed the lines correctly, I figure that means the stator coils are in OK condition.





At this point I am assuming the faulty wiring caused the regulator to fail, hence the high voltage seen.. I am still open to the possibility that the regulator could still be OK, and the faulty wiring is what caused the high voltage..

What are your thoughts on the matter?

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2nd problem I am getting is the horn isn't working. I am getting approx 11V at the horn connector (with the battery charged). I know the horn itself is functional as it sounds when I connect it to a 12V supply. When I place my DMMeter leads across the horn terminals and press the button, it doesn't register any voltage with the horn connected..

Is there a horn relay anywhere on this bike?

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I came across the electrical upgrade thread in this forum and did some reading on the MOSFET type regulators. I would like to upgrade to the SH775 regulator one time..

roadstercycle.com
 

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Useful Links
Technical help NOW!!!

>>>>> Charging system;
http://www.electrosport.com/media/pd...ng-diagram.pdf <<<< HERE`s the diagnosis chart I use...


Starter Button;
Starter Button Maintenance on Valkyries

Tire information
Tire Tech Information - Determining the Age of a Tire

VT 750 ;
SA750.com - Blacktop's ACE 750 Shop


A lot of discussion on cutting out that connector and hard wiring back together...
This connector is troublesome for sure!!!

I`d Check the entire charging system IF I were you...

Yes those burnt/corroded wires cause failure...

Good Luck & Welcome,
D
 

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Discussion Starter · #3 ·
The tire link and VT750 links seem to be broken.. but I am aware about monitoring tire age and I am pretty sure the bike I bought still has the original tires on it! lol

I came across the electrical fault finding chart before and have it saved.

Thanks for the response. As part of my repairs, I will be upgrading the wiring from the regulator to the battery and cutting out those connectors for sure! Going with the series type, Shindengen SH775 regulator..
 

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You've found the notorious p-connector a known trouble spot on all bikes regardless of brand. If you extract the terminals from their slots in the p-connector you'll find this .....



Or, maybe this ....


If electricity can't make it through that juncture your battery won't charge and it'll will gradually flat line your battery and maybe your wallet. Most owners snip off and solder the wires directly to each other eliminating the plastic connector all together. Others replace the corroded blade terminals and p-connector with new. I prefer the solder option, but that's doing things in a confined space. Btw, 15-volts might fry the electronics. Think that's the max volts for solid state thingies.

To test the stator you'd set your multimeter on AC volts. Red lead and Black lead to all the possible combinations of pairs of stator wires, p-connector disconnected, engine running, in neutral of course. AC reading should be approximately the same for all 'pairs' and AC should increase the same with higher rpm. 2nd Test, multimeter on the continuity setting (beeper). There should be no continuity between any of the stator wires and to Ground (frame). Both tests takes 2 minutes flat.
 

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Discussion Starter · #5 ·
Wow! and I thought my connectors looked bad! lol. Direct connection will be my preferred method as well.

I did the continuity test to ground and nothing came up. Will do the voltage test tomorrow.

I now finished reading the starter button maintenance thread Captain D posted. That seems like a good mod to perform next.
 

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Thanks for the heads up on that Tire link being PFFFT!
It tells us the way to see when our tires "born on" date...
0314 is third week of 2014
inside the oval shaped "brand" it lists the first two numbers as week, and second two year...
IF/w
When I have a problem with that connector, I`ll replace the spade connectors, I like that option;)

Welcome to Honda Shadow.Net, Got your patch yet?

Good Luck,
D
 

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Discussion Starter · #7 ·
Right, quick questions.

I purchased this Tachometer off Amazon.com

Bikers Choice Custom Mini Tachometer



I saw this installation video on Youtube

https://www.youtube.com/watch?v=XxKJOpgrun4

Wiring Diagram


The tach uses 4 wires for operation.
1) Ignition 12V
2) Lamp on
3) Ground
4) Green wire to negative terminal of coil

Questions:
*The Blue wire for "Lamp On" goes to a 12V+ signal from a lighted source?

*Where exactly is the 'negative terminal of coil'?


Is this the coil?


and would the negative wire be the black lead found below? (coil right of pic)


I just want to be sure before wiring it up..
 

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Discussion Starter · #8 ·


I am kinda answering my own questions at this point.. but i'd still like a confirmation since I'm new to this..
 
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