Charging system issue. Tests Good.

In the last couple weeks or so I've started having a charging fluctuation issue, where I'll look down at the voltmeter at highway speeds and the meter's down to 12v, then I'll look a few miles later and it's jumped to 14v, then in a few more miles it will drop to 13v... all at the same highway speed.

For a week before that, charge was progressively dropping until I knew I needed to open up the alternator. It was a little dirty, but the brushes were still good (one's 1/4" shorter than the other, but both still have plenty of meat left above the scribe line). I cleaned it up, fully charged my 2-year-old AGM battery (which I maintain on a Battery Tender), checked all my connections with the voltmeter and ohmmeter. Everything checks out good. It's just that now I get the randomly-fluctuating charge levels.

My presumption is that my regulator/rectifier is going bad, but I would have thought it would just die, not randomly vary the voltage output. Anyone have any experience with a similar situation? I didn't see anything else posted.

 

I STILL don't see anything else posted. :?

Can anyone throw me a bone?

 

Sounds like a bad connector under the tank that comes from the generator to the wire harness. I have twobikes that the connector has melted on

MN

 

i had a few of those plugs melt too. maybe try the battery ground at the engine, fuses, plug at the regulator, volt meter connections.
a cold solder joint in the regulator could do something like that too.
start it up and wiggle the reg plug and give it a rap tap with a screwdriver handle, see if the meter jumps

 

If you find a Connector that has MELTED, ... there's a good chance that one or more of the TERMINAL ends have pulled-out far enough to OPEN that Circuit.

This is a common issue with the Voltage Regulator to Harness Plug.
The Quick-connector overheats due to an overload.
The Terminal Ends --> Pull apart <-- due to the Connector softening.
The Male and Female Terminal Ends --- separate.

Inspect the Plug-in ends to be sure that the Terminals are still seated correctly.
Severe melting indicated the Regulator has been overheated and damaged.

 

A fluctuating charge is generally an indication of problems with the voltage regulator.

As suggested. Check the wiring connections, and also the grounds. Also try running a ground wire from the regulator case to the battery negative.

Ghost

 

Have you put a meter on the battery while running to see if that fluctuates? Has the battery actually gone flat as a result of all this?

 

I ran into a problem like that on a car. One brush was longer than the other. Turned out that the longer brush was longer because it was getting stuck in the brush holder, causing the up & down charging. Push the brushes in the holder a few times and see if it sticks, check for unusual wear on the brush and blow out the dirt and debris with compressed air. It could be the regulator, but I would check the brush holder first.

 

Unequal brush lengths are typical of this style of charging system as the outer brush has to travel a larger circle on the rotor, but it would not hurt to check that they are not sticking also. If the inner brush is the one that is shorter then you would have a sticking brush issue.

Ghost

 

Thanks all; you gave me a few considerations I hadn't thought of. Specifically, Polock's mentioning the possibility of a cold-solder joint in the regulator (or a flaky connection), and Orange-n-Black's suggestion of the sticking alternator brushes. I'll check those out more thoroughly.

MN-Maxims: I checked all the connectors, and as I suspected, nothing's melted. When I tore down and recommissioned the bike a couple years ago, I went over the entire harness and all the electrical devices, connector by connector, and cleaned or replaced connectors as appropriate. Applied dielectric grease, too. I suppose I could have an intermittent bad wire within the harness loom somewhere, but my (stationary) continuity and resistance tests are all good.

Polock: all grounds are "new" and the fusebox is "new" -- but it can't hurt to check for tightness.

RickCo: I've also had terminals slide out of the plastic harness just because the bent tang gets sloppy. I'll look closer, even though nothing's melted.

Adrian1: Yes, it went dead a couple weeks ago as the output steadily decreased. That's when I cleaned up the alternator.

Ghost: good call on the brush length issue. I thought of that, too, where the outer commutator ring covers more territory in one revolution than the inner ring, which takes more brush with it. As cheap as brushes are, I think I'll just order a set from Len and see what happens. That, and triple-check my connections for flakiness.

Thanks again, guys.

 

OK, give it a couple weeks and sure enough, the plug melts. NOW I can find it You guys are good.

This is the one you've all been talking about -- the one with three white wires from the alternator to the regulator/rectifier. I checked all the connections (even this one) back when I last posted, and everything seemed tight. The bike's even been fully charging "at speed" the last few weeks. Go figure. The telltale wisp of smoke coming up from under the seat told me I'd better take a look tonight. I'm glad I did, as I was planning on riding to work tomorrow.

So to replace this melted harness plug and the connectors, I presume I just need to check with Chacal to see what he has, eh? Hopefully some new whiz-bang bullet-proof plastic, given the way the side melted right out of this connector.

 

i replaced mine years ago with three individual connectors and i don't think i ever unplugged them since. i don't see anything wrong with soldering them and be done with it

 

Ah, the old Goldwing nemesis..............melted stator connectors

Dave F

 

Yeah, Polock, you're probably right about the soldering part... but I do like being able to disconnect if need be. Except for that whole "potential melting" thing.

 

Re: Charging system issue. Tests Good. - SOLVED

Just wanted to follow up and thank all you guys who chimed in to help me with my charging issue.

I ended up just ordering and installing new plugs/connectors from Chacal (who thankfully carries them, for all of $12 give or take).

And just to give myself some additional piece of mind, I sprang for a new regulator/rectifier unit as well. Voltmeter readings are good and solid now; I've had no issues in the miles I've ridden since. Hopefully those parts will be good for ANOTHER 31 years (bwahahaha).