So, I just had my R/R replaced (competent shop, no problems with their service). My battery is newish. Yesterday, when I went to start the bike, I get the dread buzzing, and the dash lights are dim. Unfortunately, I didn't have my trickle charger, so I hooked it to my truck (engine off). I turn the key and nothing. I figured maybe, since it is a largish battery, I might have blown the main fuse. But, upon inspection, it seems fine.

Any ideas? Where do I start to look?

Could I have killed the battery?

Could the R/R be fried? If so, how do I tell?

 

Was the R/R replaced because the old one failed? If so that could have damaged the battery you still have fitted.

Is the new R/R a Honda upgraded replacement or a Chinese copy of dubious quality?

To test the functioning of the R/R you do need a working fully charged battery (catch 22 - as you risk damaging it if the R/R isn't working correctly) - Download the Honda service manual in the workshop section and look for tests you can run with a multimeter on the battery / charging system.

Also have a search for MOSFET regulator rectifier on this forum.

 

Pretty sure it was replaced with a Honda part. I did ride for a while as the old one was going out (probably not a good idea, in retrospect). I do have another battery, I guess I could fill it and test that way.

Harbor freight multi-meter here I come.

 

Oh man, now I am really confused.

Today I go to check the bike - first I just turn the key on, to be sure it is dead. Oddly, now the bike turns on. Lights are dim, but it is getting something. Not enough juice to turn though. Just a buzz, then too little to do anything, but not completely dead (same condition as before I jumped it).

When I hit the starter, the lights dim. Trusty Harbor Freight Multi-meter test battery at 13.1v, I make sure battery connections are good, then trace back to main fuse, it is fine. Clean and dust all connections back under the tail, still the same result.

I am so confused.

 

I would remove the cables and clean both the posts and the cable ends then apply a dielectric grease. Humidity can cause corrosion that will give this type of symptom.

 

So, was the connections near the main fuse (I think the big relay on top). They have a bit of the copper connector funk on them. I think they just needed cleaning. Whoo-hoo! No trip back to the shop.