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Electrical System Tune-Up

“The Electricity’s Gotta’ Be In There Somewhere!”

By Don Hamblin
August 1998

That faithful old “K” of yours won’t start when it’s hot, the battery idiot lights “glow” weird at high or low RPM’s, you now have to pull in the clutch to start it, the gear indicator goes “blank” from time-to-time, sometimes the engine just stops, you might even be starting to actually hate the darn thing, or you’ve owned it for over three years. If you’re experiencing any of these, it’s time to “pull” a service not listed in any shop or owner’s manual. If you think that I’m asking you to add to the already long list of time consuming tasks to maintain a “K” then you could be dead (and I used that word on purpose) right! Dead, because if it hasn’t stranded or embarrassed you yet, it’s planning ondoing just that!

We’re dealing with two related problems here. Neither of which can be found in the owner’s manual or any of the shop manuals I’ve seen.

The first is that the newer (not to be confused with my older /2) BMW’s are actually reliable! (Before somebody tries to lynch me, let me say that I put almost 70,000 enjoyable miles on my R69S, tuning it up and tightening all the nuts and bolts every 2,000). You can go for so long just putting gas and oils in them that you forget that there’s other “stuff” in there that just might need attention.

The second thing is that on these “newer” rides, the old mechanical systems have been replaced by electronic systems. But more importantly, the wires no longer go directly from the generator to where the action is. The new wires are now “broken up” into shorter lengths, which are connected with “other than” copper connections (just like that new suburban assault vehicle you see in all the upscale subdivisions). That makes assembly and parts replacement easier, and therefore your retail price lower (yeah, that bike could have cost even more). Those connectors usually do work really well. Most of the time they seal out any moisture. But that also means that they can seal “in” any moisture. Where can you get moisture when you’re afraid to ride in the rain? Here in Alabama there’s more than enough in the air! (In the summer time we can’t let kids sit too long in the back yard, it’s so humid that moss grows on their north side.)

So now I’d suggest scheduling a full day, once a year, for cleaning every connection and switch contact on the entire motorcycle! I don’t mean just take the connections apart; I mean really clean them! It’s a pay me now or pay me later. If you don’t do that, expect to spend a couple of hours sitting by that gas pump waiting for something to cool off enough to let the bike run again. Or trying to find a pay phone to call somebody from the BMWMOA Anonymous Book to trailer you home. I’ve been there; it ain’t fun.

Electrical Tuneup 01

Start at the battery ground. If you hear a “creek” while you loosen the bolt, it’s a sure sign of corrosion where the electricity should be flowing through. Shades of things to come. Clean the bolt and face of the cable connector with wet or dry paper (or even an ink eraser) then coat with dielectric grease (or WD-40, Vaseline, etc.). Dielectric grease is available in a tube from NAPA dealers, but I’d found some at a Home Depot, a couple of years ago, that was “thinner” and easier to use. That will keep the corrosion from coming back for a while. Leave the ground disconnected, disconnect the other cable, and cover both connectors with electrical tape (you want electricity to flow, but not fry the semiconductors.)

Electrical Tuneup 02

Electrical Tuneup 03

Then start following the wires. Each time you find a connector, go through the cleaning. You can use a contact cleaner, but make sure that it’s compatible with insulation and plastic. Otherwise, try WD-40. Back up your work with a shop towel to keep the cleaner off the paint and other parts. “Work” the connector in and out to assure you’ve gotten the “contact patch” clean. Then apply some dielectric grease.

You’ll have to either remove or prop up the tank to get a lot of the more important connectors. The one for the ignition switch might be causing the idiot lights to all come on while you’re running. It can also cause the engine to die in the middle of your favorite curve. Just a little corrosion is all it takes. If you still have trouble with those symptoms, it might be time to just replace it. I did the cleaning and gained a couple of months “life” from mine. Long enough for mail order to catch up. Detailed cleaning instructions for the switch can be found here.

Electrical Tuneup 04

Pay close attention to the bar switches. You’d be surprised how easily they corrode. That’s where that soft glowing battery light comes from! Spray in your cleaner (or WD-40) and “work” the switch. I’ll bet that you’ll see a lot of dirt and grunge running out of the openings. Keep it up until it runs clean. Then pour in some of the dielectric grease. Help with the bar switches can also be found at:

After you’ve cleaned all the connections you can find, open the “box” for the relays. Pull each one out and clean their prongs (forks?). A connection’s a connection. Don’t skip these.

Now comes the “dirty” work. If your bike’s got over 40,000 miles on it, it’s also time to service the starter. If you’ve ever had any trouble with the starter just not turning, this might just be the problem. You’ll also have to remove the battery, but this is also a good time to inspect the pad it sits on. Paint-by-numbers directions for the starter service are at:

I’d also recommend checking the multi-pin connector for the main computer. Please be real careful with this one, it’s even more expensive than the ignition module under the tank. Just clean the connectors and apply the grease. That computer knows more about how your motorcycle is supposed to run than you do, so let it talk to the rest of the machine.

As you finish up the main wiring, watch out for stragglers. There’s the neutral switch (a loose wire there will drive your gear indicator and clutch lockout crazy)! Each and every light bulb goes into a socket. Let any of those corrode and you’ll one day find out just how dark that dark can get.

You might still have to replace a $400+ ignition control module, but at least you’ll have cut out all the easy fixes. You could actually start to like the bike again. And all this can be completed during one cold and rainy day in the garage. It’s a pay-me-now or pay-me-later, so it’s real good to schedule that payday for the middle of February – every year!

My thanks to Paul Glaves (BMWON Technical Editor), Gene Pollock (Gene Pollock Battery Service), Rick Jones (Motorrad Elektrik), Rick and Jay (at Engle Motors in Kansas City), and John Zibell (a Guzzi guy) for holding my hand while learning these valuable lessons. And also, my teenage daughter for posing in the pictures!

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