Ignition Switch failure to make contact with light circuit in the on position. Photo shows contact position when disassembled in on position. I cannot make sense of how the circuit is made for running. Center 12 v contact should be connected to the green and grey/blue wires. Green is connected and park position works fine. Jumpering between 12v and grey/blue lights the dash and headlight nicely. I have stretched the springs a bit to see if that helps but no joy. The Y shaped piece seems straight forward but the straight piece doesn't seem to make contact to 12v. Y piece moves up and down on ramps to make contact with the center 12 v contact. It also seems new switches are not available. Any help would be appreciated.
Dave
New ignition switch time ! Motorrad Eliktrik has duplicate replacements. BMW dealers cannot supply them.
Owning an old Airhead is easy.
Keeping an old Airhead running great is the true test.
Thanks, those seem to be for 1975 to 1984. Hoping to find an exact replacement.
Real OEM shows the switch itself as still available from the dealer. It's part no. 6 in the linked diagram. If that turns out not to be the case, try a google search using just the part number. You might find one used, or new-old-stock.
Chances are someone tried using a high wattage headlight bulb without first wiring power to it through a relay. That tends to burn up the contacts in the handlebar switch and ignition switch. You might get by with a light sanding of the contacts, but that removes what's left of the hardened surface they came with from the factory, and they tend not to last very long after such a repair.
Good luck, and please let us know how you make out, OK?
Thank you Scot. In searching the internet for clues I found a post on ADV about the load shedding relays. There are 2 on my bike. Only 1 is shown on the wiring diagram in my owners manual. After swapping the two relays, the headlight and dash lights came on when the ignition switch was turned on as they should. I ordered a new relay from EME here in Denver. Went for a 35 mile ride this morning to check things out and all seems to be copasetic again. I never did figure out the logic in the ignition switch but that didn't seem to end up being the problem.
I found a post on ADV about the load shedding relays. There are 2 on my bike. Only 1 is shown on the wiring diagram in my owners manual. After swapping the two relays, the headlight and dash lights came on when the ignition switch was turned on as they should. I ordered a new relay from EME here in Denver.
You took the older and proabably more expensive cure. It's the excessive current draw that heats the wires, and burns the contacts inside the required headlamp relay.
IMHO, the better path is the simple addition of an LED headlamp bulb. This drops the current requirement from 65W+ to less than 25W. That's a 61% drop in current over the std 65W bulb, and a whopping 75% reduction in current over the commonly installed 100W bulb.
• With the LED bulb, the relays are no longer needed and can then be removed... thus simplifying the electrical system.
• The current that's not used by the HL bulb then ends up maintaining the battery better.
• AND to top it all off... an LED HL bulb creates more light than a 100W halogen bulb ever dreamed of.
More light, less complication.
Owning an old Airhead is easy.
Keeping an old Airhead running great is the true test.
Thank you Richard, that is information I did not have before.
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