Topic: 1975 cb550f electric problems...

[alarche]

hey everyone,

i keep blowing out the "main" fuse on my bike when i turn the ignition key to "on" position. none of the lights work now. it  used to  until the headlight fell (while i was disconnecting it) and now i have the problem. any help will be appreciated.

[oldbiker]

Replace the fuse by a spare 12v bulb. This will protect the system while you fault find. Switch on and the bulb will light because of the fault. You can now search around until you find the fault and the bulb  goes out. Repair the fault and then replace the fuse. Once you have fixed the short circuit, you will be able to sort out why the lights are not coming on.

[cbjunkie]

keep your eyes open for smoke.   

[oldbiker]

There won't be any smoke, the bulb keeps any current flow to a safe level.

[cbjunkie]

thanks - i'll try to remember that, it's a good "trick"

[alarche]

thanks...i'll try doing that...i'll keep you posted.

[grumburg]

Would start with the headlight plug. Make sure the little spring clips at the end of the wires fit tightly in the slots in the plastic plug with no bare insulation. Also check for loose or broken prongs on the sealed beam. Will short against anything when light is pushed in. Try to see if fuse blows with headlight removed. Took me an hour and 2 blown fuses to track down a loose headlight plug.

[RyanLilly]

I have seen "fuses" that were actually light bulbs, always wondered what they were for. Now I know. Thanks.

[alarche]

it still blows out when the headlight is out...this is really frustrating ...i checked how much power is going thru when the ignition is in "off" position and everything ckecks out. it's only when the ignition is in "on" position that this happens. i'm new to this so i apoloogize in case i am asking dumb questions..