The ignition switch in my '93 R100GS PD failed a while ago, and I replaced it with a generic switch from Euro Moto Elektrik. Not pretty, but it works. Lately I've had intermittent trouble turning the bike off when I'm done riding. The switch seems to have no effect. I've had to pull the hot wire off the back of the switch to turn the bike off. Today the switch is working fine, so I suspect it's something else. Is there any way the load shedding relay could be failing and cause this to happen?
Thanks,
John
• You might call Euro Moto Elektrik and see if there are reported issues with the switch.
• I'm not aware of a relay in the ignition system, but then I've never even touched a GS. The ignition system is such a low current device that I see no need for one.
• I'd be probing the rear of the switch with a mechanic's test light to see what's happening in the different key positions. Are you sure you have the battery connected to the correct input contact ?
Owning an old Airhead is easy.
Keeping an old Airhead running great is the true test.
Thanks, Richard, for the post. I will talk to EME about the switch if it turns out to be the culprit. There are relays in the system, both for the starter and to shed load during cranking. This is not an ignition issue as the bike runs fine. Yes, I have the electricity going to the right places.
John
To clarify for readers who may want to know, did the replacement switch come from Euro Motoelectrics (EME) or, Motorrad Elektrik (Rick Jones) ?
The replacement switch is from Euro Moto Elektrik. Specifically this one: https://www.euromotoelectrics.com/product-p/ignswitch273.htm
The OEM switch is unobtanium as far as I can see.
Took the bike for a long ride today with a few stops along the way. The problem did not happen again. Strange...
There are relays in the system, both for the starter and to shed load during cranking.
• Starter relay is not part of the ignition system. That's connected to the starter button and sends current to the starter solenoid.
• The load shed relay turns OFF the headlamp (the 2nd highest current user in the electrical system) during cranking so that the starter motor (the highest current user in the electrical system) will have max current available. It is also controlled buy the starter button and is not part of the ignition system.
I stand by my statement. I am unaware of any relay in the ignition system.
Owning an old Airhead is easy.
Keeping an old Airhead running great is the true test.
I have been pondering this topic for a few days.
Lately I've had intermittent trouble turning the bike off when I'm done riding. The switch seems to have no effect. I've had to pull the hot wire off the back of the switch to turn the bike off.
When you pull the 12v source (hot) wire off of the back of the switch to stop the motor, you are doing the job that the switch is supposed to do. That would make me wary of the main switch being reliable. As a matter of practice, you might use the kill switch to stop the motor. Like Richard, I can not think of anything like an ignition relay in the OEM design.
former Airmarshal, IL.
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