R/R vs Stator.. Where is the problem?

Hey all.... my '90 gen 3 is having charging issues. Here's what i've done so far. Removed Regulator/Rectifier (SH612-12) and checked it with voltmeter. Here's my numbers:

510 509 505
0 0 0
0 0 0
481 503 501

That being said, I'm assuming it's still good. All wires to and from battery, to stator, and to RR are in great shape. There are no visible burned, chaffed or corroded wires. Next, I checked the stator with voltmeter and it did not show to be grounding out at any pole. The bike has not had a battery hooked to it in some time. Would that matter when checking the stator? My next step is to reinstall the R/R and check my battery at idle, 5k RPM's and with headlight on and high beam to test voltage variances and see if stator is charging. Any tips greatly appreciated. My batter is about 4 years old but it charges ok and tests ok, but it still could be the issue and I'm not ruling that out. I won't be able to work on this for a couple of weeks but weather is getting nice and want to ride.

 

What is the charging issue?

Are you checking electrical components hot or cold?

Stator will get checked for continuity to ground, but also a/c voltage between the legs. What are those measurements?

I've never found a meter to help much with disconnected r/r checking. But you should be able to measure dc voltage out with bike off, bike at idle, and bike at RPM (use the manual to find out what RPM.

Have you checked all related connectors/grounds as listen dozens of times in this and the other VFR forum? There's a ton of great info already typed...

I'd surely not diagnose a VFR electrical issue with an unknown battery. Maybe run it off of a known battery or your car?

 

There's a decent fault finding flowchart available from Electrosport. https://www.electrosport.com/pages/technical-resources

My short version is if the voltage reads 13.5-14.5V across the battery terminals at 5000rpm, then the charging system (alternator/rectifier/regulator) is fine. If the fault is hard/slow/non-starting then the battery would be my first replacement.

Any lower voltage at the battery means the charging system is faulty. You can do a voltage measurement off the running alternator, and should see something like 50V AC across each wire pair.

 

Thank you all for your replies. I always appreciate the knowledge shared here on this site. I know it comes from tried & true experience.

@bmart: Thank you for your reply! I'm sorry! I didn't even explain the issue I'm having. In summary: Started with a fully charged battery and drove about 20 miles. It ran great until the battery died. Recharged battery to full (13.2 V) and tested battery while idling and revving to ~ 4-5k RPM. The only fluctuation in the battery during any of this was ... DOWN. I will try what you mentioned: "measure dc voltage out with bike off, bike at idle, and bike at RPM". Yes, I've inspected every visible wire possible in the loop that I can find. If there's a connection mid-body that I cannot see, then it has not been inspected/tested. I would hope there are no spliced wires from the stator or battery in the connection stuck randomly in the middle but stranger things have happened. Also of note, this is the original R/R and stator. Interesting that you have not found a voltmeter to help much with a disconnected R/R. I was also wondering if the numbers I received could be deceiving and yet still have a bad component. I like your idea of testing the R/R and will try this asap. I will also take my battery to have it tested and purchase a new one if there is any doubt.

@Terry Smith: Thank you for your reply and I really appreciate the link! I am going over it now and it seems very detailed and VERY helpful. Really appreciate it.

It will be a bit before I can complete all these tasks but I'll post my results, discoveries and hopefully the FIX asap.

Thanks all!~~~