Indicator problem - this should be so easy.... but

[Anonymous]

Hi
Since yesterday, the left hand indicators on my bike ('82 GS750TZ) don't work. The front left indicator lights but doesn't flash, the rear left doesn't light at all.
The right hand indicators are working fine as normal.
I changed the bulb in the rear left. No change. I tried the new bulb in the right indicator - it worked. I tried the right bulb in the left indicator - it doesn't work. i.e. it's not a problem with the bulb.
I had a bit of trouble getting the old bulb out of the left - unlike the right side, it was corroded in.
I noticed that the right indicator has a light blue wire going through the nut at the back of it and a black and white wire attached to the side (Clymer manual shows a green wire and a black and white).
The left indicator also has a light blue wire going into the back of it. There's a broken connection at the side of the bulb and a brown wire dangling down (again, Clymer shows a black wire and a black and white). Unfortunately, the obvious solution of reconnecting this brown wire, doesn't fix the problem.
Please, what do I try next?

Roger
"The Estimable Mrs Smith - 1982 GS750TZ"

[Jay B]

Wires

Without actually looking at it I would suspect that that broken wire broke due to corrosion. That being the case I would also suspect that it is your ground wire. Re Connect it and then find where it grounds to the frame and clean that connection. Your lights should then work again. Also get yourself some contact cleaner and clean out the socket. Then find out if you getting water into that area and plug/seal it up.

[Alan Schlosser]

Obviously, You aren't completing the circuit on the left side for the indicator to work. Bottom line is that you need to get a DVM, disconnect the hot and ground to the left rear turn signal and check for continuity. You should get a reading through the hot to ground, anything but an open. If the socket is corroded, you may have lost the connection. You could also use a little extra wire and try lighting the bulb (in the socket) by connecting it right to a battery. Good luck.

[argonsagas]

Obviously, you have some heavy corrosion. If you don't win with the contact cleaner, try wrapping emery cloth around the blunt end of a pencil. Push it against the contact and turn at the same time until the contact shines. Run the emery cloth up/ down and around the body of the socket as well, to clean off all heavy junk along the sides.

Check the wires that come out of the socket for corrosion, and look closely at the centre contact piece, as sometimes it is a fitting that is crimped in place, in which case corrosion could be inside the crimped area and you have no contact, even though it feels tight.

Pull it apart and solder a clean connection.

A simple way to check the centre contact is use a pin and insert it into the wire behind the socket, connect your DVM/VOM to the pin and the contact and verify continuity. Tape the area where you put in the pin.

[Anonymous]

Thanks but still not working

Thanks for your replies. A big part of the problem is my almost total lack of understanding of electrics. I can use a volmeter to measure the voltage of a battery and that's it. Other than that, I have no idea what I'm doing. The only good thing about this is that at least I don't THINK I know what I'm doing!
Yes, the electrics are in a bad state - even I can see that. Tons of corrosion. This is due to a hole in the seat. That's another thing for my list - a new seat. I cleaned what I could today, wrapped tape round frayed bits, soldered the broken wire and replaced one of those plastic connector things but still no go. I'd assumed that the wiring of the right and left sides would be symetrical and that if I could see how the right side was wired I could just copy it on the left. However, that's not the case. There's a whole bunch of wires going into a sort of sheath. I noticed that if I wiggle them around, I can make the right indicator fail too. Unfortunately, none of the wires from the left indicator seem to be included in that bunch so it looks like there's another problem waiting to happen. Oh well.
If you have any other ideas I'd be really grateful.

Roger