Motorcycle Repair: wiring on a 1991 Kawasaki EX500A, electrical gremlins, vital ground

Question
Hello Bill,

Thanks for taking the time to review my problem. I have a 1991 EX500A. If I turn my key all the way forward I have tail lights and licence plate lights but when I turn it back a notch (into the start position) I loose all lights to the back of the bike except for the right rear blinker which has a really small glow to it with the bike running. I looked at the wires for any breaks or burns and they all look okay. Everything was working fine last summer. How would I go about testing something like this rather than just looking for broken wires?

Thanks
Michael
magicsun@optonline.net

Answer
Micheal... it sounds like a defective ignition switch to me. The internal contacts can get corroded, especially when the bike sits for a long time. Try cycling the switch through all positions several times quickly and check the harness connector to the switch as well. Mounted on the handlebars, the switches can work the wires a lot and the connectors get damaged/loose.

Weird electrical gremlins also surface when the battery is put in backwards or vital ground connections are lost. Check your battery ground connection to the bike frame/engine and grounds for the wiring harness first, assuming that the problem is not in the switch itself.

Be sure that your fuses are all okay. Sometimes they will get a fracture inside and still look okay.

Bill Silver