Motorcycle Repair: Electrical Problems, honda nighthawk 650, turn signal switch

Question
QUESTION: I have a 1984 Honda Nighthawk 650.  The turn signals, brake light, and horn do not work.  I have been trying to isolate the problem for a few weeks now.  All the fuses look good.  I have replaced any faulty bulbs.  I have replaced the turn signal relay. Do you have any suggestions?

ANSWER: Hi Nate,
The best way to deal with electrical issues often is with a service manual that has the wiring diagrams. A broken wire or something plugged into the wrong connector on the harness somewhere could cause the issue you describe. Look for anything in the wiring harness that appears to be repaired or re-taped. New tape, solder or crimp on connectors could help to narrow down the issue.
Regards,
Terry.

---------- FOLLOW-UP ----------

QUESTION: I have a service manual with a wire diagram and have been chasing wires for two weeks.  I have taken voltage readings a various spots as well.  I notice that I can get 10.5 volts at the turn signal switch but when I use the switch, I do not get any voltage on the side that I am trying to get a turn signal indication.  I have bypassed the switch and I can get all the lights to come one but there is no flashing.  I am not get any voltage to the turn signal relay either, but the wires show good continuity.  Could it be in the switch?  That is a pretty expensive part for me, so I wanted to make sure before I replace it.  Any tips on how to confirm this?

Answer
Hi Nate,
It sounds like you have a broken wire somewhere, if the voltage is dropping to near zero when you activate the switch this likely indicates an open circuit somewhere in the electrical system. You can prove or eliminate the switch as the problem by using a jumper wire across the switch contacts. Connect the jumper wire to the terminals on the switch that would be connected together when the switch is activated. If the signals flash with the jumper this indicates the switch is faulty, if the problem stays the same then the switch is ok. It may be a broken wire where the harness goes around the steering head, the wires have to flex here when the handle bars are turned. The continuity test often won't show intermittent issues and if the wire is broken and just making contact it may measure ok with a continuity test but when a load is attached (lamp & relay) it will fail to pass the voltage.
Regards,
Terry.