Questionhey, so i have a 1982 Honda gl500 that i bought over this past summer. the guy i bought it from told me the headlight didn't work and he didn't know why so i recently began trying to find out what the problem was. my first thought was obviously to try just replacing the light, so when that didn't work i replaced the wiring harness and its still not working. any ideas?
AnswerThe first thing to check is the fuses. Don't trust a visual check - glass cartridge fuses are notorious for having the weld between the link and an end cap fail, leaving a perfect looking fuse that does not conduct. In a pinch you can check a fuse by holding one end between the fingers of one hand and flicking the other end with a finger of the other hand (if the link vibrates the weld has failed), but the best way to check them is in circuit using a voltmeter.
- Remove the fusebox cover in the middle of the handlebars.
- Connect the black lead of the meter to a known good ground point. The engine mount bolt where the lead from battery - is connected is usually good.
- Turn the key on and measure the voltage at each end of the fuse you suspect. It won't hurt to check all the fuses - I usually do when I have the cover off in case there is a problem I haven't noticed yet. If any fuse has different voltage from end to end it should be replaced.
If the fuses are all good the next thing to check is the START button. The START button has a second set of contacts that turns off the headlight while the button is pressed so that there is more power available for the starter motor. Over the years the contacts can become oxidized or the grease in the switch can become contaminated with dirt or can become hard.
I recommend spraying the switch with contact cleaner before you take it apart.
Note: You need to have real contact cleaner. WD40 is a fine product and has many uses, but it is not real contact cleaner. It leaves a sticky residue that will attract dust and you will have dirty contacts again before you know it.
You can usually clean the switches on the handlebars without taking anything apart. If you look at the bottoms of your switch clusters you will see that there are small holes, just the right size to accept the straw from the contact cleaner and located so that it will spray right onto the contacts.
Just spray the contact cleaner into the hole and work the switch or button vigorously several times, then turn on the key & try it. You might need to repeat the process several times before it works properly.
If you can't get it working after 3 or 4 tries you will need to take it apart.
If you find broken parts you will need to make a trip to the wreckers.
If there is just too much dirt & hardened grease in there for the contact cleaner to wash out you will need to clean it manually. Use an old toothbrush & more contact cleaner.
DO NOT use sandpaper - particles of the grit will become imbedded into the contact's surface and cause all kinds of problems.
If a contact is pitted you can dress it with a POINTS FILE. DO NOT use a regular file. POINTS FILES are designed for dressing ignition points and have the their teeth cut at the proper angle &c so that they will leave a very smooth surface.
I also recommend joining a good forum that caters to bikes like yours. You will find that someone there usually has had the same problem you have and figured out how to fix it of has tried what you want to do and can tell you if it will work before you spend a lot of time & money.
http://choppercharles.com/cs/forums/ is one of the best for the CX/GL500/650 family. I look forward to meeting you there - my winter machine is a CX650.
