Problem with charging system


Short version for the impatient ones: noticed that the voltage started dropping below 13.0V, discovered that the generator connector (with 3 yellow wires; under the tank) almost disintegrated inside.

Long version:

So, I have a track day coming. I rode last weekend and noticed that the voltage on the battery consistently dips under 13.0V.

How did I notice? Because I have a cheapo RadioShack V-meter installed on the bike and permanently connected to the battery.

Anyways, the next day I remove the tail plastics, lift the tank and start troubleshooting. I got to the generator connector, and Holy Crap! The female connector (goes from the generator) is all filled with some goo, and the male connector is all rotten away sort of, so badly that I just pulled it and it came off while the wires inside are just hanging.

I was glad I found the problem. The fix wasn't easy though. You can't just replace the connector. So, first, I replaced the female connector going from the generator. There was enough slack in the wires. So I cut the connector off and crimped on quick disconnects. They are 1/4" and mated with the other side fine. I figured I will just insulate the bare connectors coming from the voltage regulator.

Started the bike, voltage is good. However, the connectors were so hot, I almost burned my fingers.

At this point, I decided to replace male connector, or what's left of it. The problem was the wires coming from the harness are too short. So, I took a scalpel and did a bit of a surgery - carefully cut through the wrapping on the harness and managed to expose another inch or two of the yellow wires - at least some room to work. I cut the burned ends, and crimped on male connectors.

Put it all together, started the bike, and the connectors and surrounding wiring are barely warm. To test it completely, I turned both lights on and waited for the fan to come on. Still warm, but I can hold my fingers there with no problem. Stuffed connectors with dialectric grease and closed them up.

Went for a test ride and all seemed good. I spent good 3-4 hours on that. I had to do it slowly and carefully because there was no room for mistake. And because there isn't a lot of room to work under the tank, and not enough lights. Whew!

In retrospect, I remember smelling burned plastic or wiring a few times, but could never figure it out. Now I know what that was.

While I was in there, I tested all diodes in the voltage regulator (per manual), resistance of the coils, and no load voltage of the generator - all were good.

Now that I think about it, this connector is the most critical part of the electrical system when it comes to poor contact. That's because this connector carries the current for the entire bike - headlights, fan, ignition system. So, if the main fuse is for 30 Amp, this means this connector can easily carry a current of up to 20 Amps. That's not peanuts. A smallest degradation of the contacts would generate a pretty good amount of heat. This in turn contributes to the contact degradation. So, the whole process accelerates over time.

An easy way to check your bike for a poor contact in this connector is to simply touch it when the bike is running - preferably when both lights and the fan are all ON. If it's so hot you can't hold your fingers on it, you've got a problem.

I also want to point out that if not for the V-meter I installed, I would've never known. Eventually, the battery would be discharging, even during the ride. In such case, either of two things would've happened. I wouldn't be able to start the bike at some point of time, possibly in the middle of nowhere.
Or the bike would simply die while running - because of lack of electrical power to power the spark plugs, injectors, and/or fuel pump.

I still have a bit of a mystery. About a year ago I was cleaning all connectors, including this one, and I saw some oily stuff in there, which I could never figure out where it came from. At the time, I cleaned the best I could using a contact cleaner, a paper towel, and what not. I guess that wasn't good enough. I didn't realize the ramifications of poor contact for this specific connector, and never checked for how much it would heat up when the bike was running. So, whatever that oily stuff was, that's what started this chain reaction years ago, gradually degrading the charging system.


Bad connections are a killer.Mine was overcharging so I bought a new R/R.I used dielectric grease where the connectors go together.I may check the connector from the stator to be safe.


Wow your not kidding about that having a long version. I had a connector melt on my car and it shorted out and melted a hole in my line to my NOS purge solenoid.... Braided lines are apparently good grounds lol (I was 17 have learned much since then)



I was installing my new ScottOiler yesterday and found my connector in the same situation. I am in Germany and don't know where to buy a connector like the factory. What type and where did you buy yours? I appreciate your input and your article was exactly my problem as well. My bike has been charging fine at idle but when you give it gas it drops in voltage. I replace the R/R and the voltage went up to normal but everytime I rev it up, the volts drop.

Let me know what type of connectors to use, there is a Conrad(Electronics) store over in Mainz. I could run over there today. There are several automotive stores in this area as well. The plastic is very thick and I just don't want to buy another sub-standard connector(sorry ass Suzuki connector).