Ground and/or signal light problem

[Sirrus]

I believe I have a ground problem on a 1980 1100 special. My signal lights rarely work. Every now and then one side will come on but not flash. Just stays the solid orange. This usually happens shortly after I start the bike. If one side does come on, I can make alternate the sides via the switch but neither will blink. Once I turn them off, they won't come on again the rest of the ride. Everything else, electrical wise, works. Headlight, tail light, brake, and 4 way flashers work as intended. How would I go about diagnosing this problem?

[FANNING507]

Check the connection under the seat. Everytime mine does that, it's that connection spot. That's the easiest to check. The handle bar switch is probably a weak spot too, but pay attention when disassembling it. Lots of parts in there.

[CatatonicBug]

Open up the left handlbar switch and take the switch apart. There are lots of connections and moving parts that can get corroded. Once you clean the corrosion off, be sure to lube it with dielectric grease, and reassemble. Also check the lightbulbs. If one bulb is out, it will not allow them to flash on that side (but they will come on solid). They also have to be the right wattage bulb if you are using the stock flasher.

You might also want to check the other connectors on the bike, to be sure they are clean, and corrosion-free. Ground connections are especially important.

[Sirrus]

Which spot or what am I looking for under the seat? I forgot to mention that this happened once about 4 months ago. I took out and checked all the fuses, which were all good, and they started working again. Also, how could the bulbs be bad if they work ie blink when the 4 ways are on?

[Tom Andersen]

Under the seat on top of the plastic inner liner there is a boot with four wires going into it. Just slide it back to expose the connections.

I replaced my flasher unit with an electronic one from NAPA, the automatic canceling doesn't work anymore but everything flashes great.

[bikerphil]

I took out and checked all the fuses, which were all good, and they started working again.

The clips that hold the glass fuses in become weak and do not make a good connection. Replacing the fuse box with a newer blade type will eliminate all sorts of electrical gremlins. Member Topcat sells them for about $10.

[CatatonicBug]

Also, how could the bulbs be bad if they work ie blink when the 4 ways are on?

The 4-ways use a different flasher than the signals. The signal flasher is mounted just below the fuse block, while the 4-way flasher is under the seat, just in front of the battery, on the left side of center. It's not that the bulbs are "bad", but the OEM signal flasher is a thermal flasher, and requires a certain amount of current draw to activate. It acts as a dead bulb indicator, not flashing if one bulb is dead, so you know the bulb is dead by looking at the non-flashing dash indicator. If the bulbs are not the correct wattage, they won't pull the right current, not allowing the flasher to... flash.

[Sirrus]

Looks like I will be taking the switch on the handle apart. I tried everything else with no avail. Thanks for the advice.