The Airheads Beemer Club is a non-profit club reclaiming the 'Legendary Motorcycles of Germany'

Topic-icon 1.5 amp current leak

  • jdeez1
  • jdeez1's Avatar Topic Author
  • Offline
  • R100 Level
  • R100 Level
More
5 months 5 days ago #3628 by jdeez1
1.5 amp current leak was created by jdeez1
I have a 1.5 amp current leak in my 1987 R80. I have tracked it down to this black and blue wire connector under the tank. Looking for what these wires are used for. Thanks
Attachments:

Please Log in to join the conversation.

  • jdeez1
  • jdeez1's Avatar Topic Author
  • Offline
  • R100 Level
  • R100 Level
More
5 months 5 days ago #3629 by jdeez1
Replied by jdeez1 on topic 1.5 amp current leak
Further testing has revealed that it is the low beam of the headlight. Now I am looking for ideas on how to isolate it from the wires that go forward into the loom and the wires the go down into the engine case. Any input is greatly appreciated.

Please Log in to join the conversation.

  • jdeez1
  • jdeez1's Avatar Topic Author
  • Offline
  • R100 Level
  • R100 Level
More
5 months 5 days ago #3630 by jdeez1
Replied by jdeez1 on topic 1.5 amp current leak
Tested the connection. The blue wire is grounded on the front half of the plug (look like it goes forward into the loom). On the other side of the plug (female that goes down into the engine case) the black wire goes to ground. I'm assuming BMW used "black" for the ground wire. So that means my problem is on the front half? The (male) side of the plug?

Please Log in to join the conversation.

  • jdeez1
  • jdeez1's Avatar Topic Author
  • Offline
  • R100 Level
  • R100 Level
More
5 months 5 days ago #3631 by jdeez1
Replied by jdeez1 on topic 1.5 amp current leak
I have found that with this connector disconnected the High beam lead (at the bulb) is showing that it is grounded. Um guessing that is a problem

Please Log in to join the conversation.

  • jdeez1
  • jdeez1's Avatar Topic Author
  • Offline
  • R100 Level
  • R100 Level
More
5 months 5 days ago #3632 by jdeez1
Replied by jdeez1 on topic 1.5 amp current leak
I have found that with this connector disconnected the High beam lead (at the bulb) is showing that it is grounded. I amm guessing that might be the problem?

Please Log in to join the conversation.

More
5 months 5 days ago - 5 months 5 days ago #3633 by Wobbly
Replied by Wobbly on topic 1.5 amp current leak
I don't doubt that you have uncooperative harness that is loosing battery power with the ignition in the OFF position, but highly doubt that your "short" is in the Low beam. Using meters for testing can give misleading results, and I am assuming you have fallen into one of those traps.

Issues with Low beam would be on the Yellow wire. A simple test for that might be to place an ammeter between the battery and one of its leads, detect the loss you're describing, then simply unplug the headlamp bulb. Unless the ignition switch has failed internally, all power is cut to the lighting circuits when that switch is OFF. Most failures of the ignition switch are failures to make connection not continue connections, so that doesn't make sense.

However, the charging circuit uses a Blue wire, and in fact (according to a schematic) the only 2 wire connector with both Blue and Black wires runs to the voltage regulator. (The Black wire triggers the starter motor.) If the voltage regulator contacts failed to open with loss of power on Blue, then it might continue to power the alternator field with a low level loss of the type you describe.

I would encourage you to simply try another voltage regulator. Since Bosch was the original supplier all the 3 plug regulators are the same, so borrowing one from a friend's Airhead is the way to go. If you simply can't find one, then you can get a new one off Ebay for a whopping $17 (see item 272655228783 ). This is a German made after market part that is solid state. If your bike is still using the regulator with the steel can, then this is a definite charging system upgrade. So even if your issue persists, this is still a good purchase. But in all honesty, I think it will help with your problem.

BTW... Brown, not Black, is the system Return wire.

All the best.

Don't hide 'em, Ride 'em !!
#15150
Last edit: 5 months 5 days ago by Wobbly.

Please Log in to join the conversation.

Moderators: Wobbly
Time to create page: 0.940 seconds