Need some Regulator Rectifier help

Need some r/r advice. I am pretty mechanical but not with elecrical systems, so please bear with me.

1997 VFR750, about 10,000 miIes, went for a ride yesterday, it was very hot and i was riding pretty hard. Brand new battery (old one died? maybe not>is it the r/r)).

Anywho... bike died at a stop light and would not restart, only a few click of the starter, r/r was very, very hot to the touch. Recharged the battery at a gas station and made it home. Put a volt meter on the battery and it showed no increase in volts as I revved the bike. I assume it's not charging?

Here is one of my questions, I tested the r/r according to the service manual and there was no change in the reading on the ohm meter between ANY of the connectors. According to manual it shoud be between .5 and 1.

What is the ohm reading of a bad r/r between connector pins?

I also tested the ohms between yellow wires on the 5 pin plug and each read .7, although the manual stated between 1 and 2, is this something to be worried about?

Lastly I tried to perform the charging test which made no sense- the manual tells you to remove the starter fuse, then to start the bike, how can that be done?

Other than that the r/r looks OK, the wiring is fine, the bike has about 10,000 miles, all connectors are corrosion free.

Any help?? Anything I am missing?

Diode check should have continity one way but reversing the leads , no continutiy at all.

I would start with the stator, everything originates from there. disconnect the 3 yellow wires and do the ground check , each of these wires to ground. Meter on the highest ohm setting to detect the slightest bit of continuity. There should be none, and then about 1k ohm between the wires.

My last 2 stator failures(different bikes), I've had to go no further than that stator ground check,

if you make it that far with it checking out then you can start the bike and check ac voltage on three yellow wires(60vac, but I've yet needed to do that, since both mine were shorted stators. The key is the high ohms scale, many miss that and test on a low scale, not the detecting the shorted stator

I think electrolux or something like that has a nice write up to be more detailed.

Even the shops will tell you until they have a known good stator functioning, you cant throughly check out an RR other than a diode check. Which if the diodes are breaking down and leaking will give erroneous voltage.

Hopefully this of some quick value

[image: View Post]spud786, on 14 June 2010 - 09:01 PM, said:

Diode check should have continity one way but reversing the leads , no continutiy at all.

I would start with the stator, everything originates from there. disconnect the 3 yellow wires and do the ground check , each of these wires to ground. Meter on the highest ohm setting to detect the slightest bit of continuity. There should be none, and then about 1k ohm between the wires.

My last 2 stator failures(different bikes), I've had to go no further than that stator ground check,

if you make it that far with it checking out then you can start the bike and check ac voltage on three yellow wires(60vac, but I've yet needed to do that, since both mine were shorted stators. The key is the high ohms scale, many miss that and test on a low scale, not the detecting the shorted stator

I think electrolux or something like that has a nice write up to be more detailed.

Even the shops will tell you until they have a known good stator functioning, you cant throughly check out an RR other than a diode check. Which if the diodes are breaking down and leaking will give erroneous voltage.

Hopefully this of some quick value


I'm not to good at electrics, is a continuity test the same as checking the resistance (ohms), what setting for a continuity test, what should the reading be if there is (or is not) continuity?

Where is the stator plug, or can I use the 3 yellow wires coming from the r/r plug. So, using these three wires, I should check voltage with the bike running?

I appreciate your help, this is pretty frusterating...

The 3 yellow wire plug, comes from the stator on left side of motor to the RR , your RR may be on the rear of the bike,, but the fat 3 yellow wire plug is the only one on the bike. disconnect and check the stator side wires to ground looking for short, run highest megaohm setting. as mention previous, no continity with oms check at all, to ground on any of the stator yellow wires,

Follow the yellow brick road

Download and print out that step-by-step flowchart. Make sure you start with a fully-charged battery that can actually HOLD charge or everything you do on the flowchart will be off.

It's as simple as that to find the bad components.

In the end though, it's probably a bad connector or 12 and a bad ground connection -the most overlooked issue with the R/R charging system.