Hi, I'm new to this forum and to motorcycles in general. I've been working on my Radian for some time now. I got the thing running after I bought a new battery and fuse box for it but the turn signals never worked. Slowly the bike got worse and stopped running and even stopped turning on. Since then I have replaced the whole wire harness and the starter solenoid. After that I was able to turn it on only if I jiggled the key around in the ignition. When it turned on I couldn't start it or get any of the electrical components to work other than the horn (which sounded very weak/quiet). At this point I have no idea what issues I may be having. Could someone help? Thanks guys!
87 Yamaha YX600 Radian Electrical Problems
- Thread starter danv93
- Start date
If you don't have a multimeter, you'll want to get get one. We'll wait. 
OK... now that you have your multimeter, it's time to start tracing voltage. We start at the beginning (the battery) and trace all the way through the circuits until we find the problem.
First measurement is between the two terminals of the battery. You should get 12.4V or 12.5V on good battery. Anything less is a bit low and anything under 12V is usually cause for a new battery (batteries can be load tested at most shops and they will do this for free).
Next measurement is to verify the ground strap. With the red probe still on battery +, touch the black probe to bare metal on the bike (engine or frame or whatever is fine) and you should get the same reading as before. If not, you have a bad ground or ground strap for your battery.
Up next is the solenoid. The thick wire from battery + should go directly to the solenoid. Check power here again.
From the solenoid, find the thick red wire leading to the fuse box. This is your main power wire. Check again, both before and after the fuse.
The red wire then splits and heads off to the regulator/rectifier as well as the ignition switch. Ignore the former for now and focus on the latter. Check for voltage before the switch. Turn the switch on and now check for voltage after on the brown and/or blue wires.
The brown wire should feed back to the fuse box and be split off for the various circuits from there.
This will be a time consuming task, but it's the only way to know for sure where the problem it.
OK... now that you have your multimeter, it's time to start tracing voltage. We start at the beginning (the battery) and trace all the way through the circuits until we find the problem.
First measurement is between the two terminals of the battery. You should get 12.4V or 12.5V on good battery. Anything less is a bit low and anything under 12V is usually cause for a new battery (batteries can be load tested at most shops and they will do this for free).
Next measurement is to verify the ground strap. With the red probe still on battery +, touch the black probe to bare metal on the bike (engine or frame or whatever is fine) and you should get the same reading as before. If not, you have a bad ground or ground strap for your battery.
Up next is the solenoid. The thick wire from battery + should go directly to the solenoid. Check power here again.
From the solenoid, find the thick red wire leading to the fuse box. This is your main power wire. Check again, both before and after the fuse.
The red wire then splits and heads off to the regulator/rectifier as well as the ignition switch. Ignore the former for now and focus on the latter. Check for voltage before the switch. Turn the switch on and now check for voltage after on the brown and/or blue wires.
The brown wire should feed back to the fuse box and be split off for the various circuits from there.
This will be a time consuming task, but it's the only way to know for sure where the problem it.
