Mystery turn signal problem

[Strick]

Here goes:

Right turn signal turn on, and rarely flash
Left turn signal won't turn on.

I have swapped sides with the wires and the right turn signal switch on will turn on the left, so no bulb issues or ground issues. I just swapped sides with the wires under the seat and in the headlight.

I checked the indicator bulbs in the dash and both are good. I checked all connections in the headlight, and near the battery, and all wires are properly connected.

I bought a second handlebar control switch, and same thing - no left side turn signal.

I even removed the control signal control box and jumpered the wires - once again right side works, not the left.

Any and all suggestions or advice is welcomed --> HELP!

1979 GS1000L

Thanks Guys!

[piester]

I went through a great deal of problems with my signals recently. First off if it has self canceling lights unplug the box that controles that. The signals should work without it. Mine do just fine. Next. Make sure all of the bulbs are 12v 23w bulbs. This system will work with any bulbs from 12w up to 36w. The only difference will be how fast they flash. But 23w is the stock bulb. Also make sure all bulbs have a good ground. Run dedicated grounds for each bulb If you have to. I don't know what flashers will work with this system thow. I have only had luck with stock flashers. Check fuses and the stock wiring and all connections including where the bulbs go into the sockets.

[Steve]

Are you testing your signals with the engine running? What is your battery voltage when you are testing the signals?

May not seem like much, but the turn signals are rather voltage-dependant. Even with the engine running, if you are at a stop light and have the brake on, there might not be enough to flash the signals. Either take the brake off or run the engine just a little faster (about 1500 rpm) and they will probably flash. If you are simply turning the key on and checking the signals, you might have as much as 12 volts if you have a good battery or it could be considerably less.

.

[Strick]

I went through a great deal of problems with my signals recently. First off if it has self canceling lights unplug the box that controles that. The signals should work without it. Mine do just fine. Next. Make sure all of the bulbs are 12v 23w bulbs. This system will work with any bulbs from 12w up to 36w. The only difference will be how fast they flash. But 23w is the stock bulb. Also make sure all bulbs have a good ground. Run dedicated grounds for each bulb If you have to. I don't know what flashers will work with this system thow. I have only had luck with stock flashers. Check fuses and the stock wiring and all connections including where the bulbs go into the sockets.

I did remove the box during my troubleshooting and the same thing happens. I will reground the bulb sockets and give it a try.

[Strick]

Are you testing your signals with the engine running? What is your battery voltage when you are testing the signals?

May not seem like much, but the turn signals are rather voltage-dependant. Even with the engine running, if you are at a stop light and have the brake on, there might not be enough to flash the signals. Either take the brake off or run the engine just a little faster (about 1500 rpm) and they will probably flash. If you are simply turning the key on and checking the signals, you might have as much as 12 volts if you have a good battery or it could be considerably less.

Well, you got me on this one. I just had the key on. I'll give it a try running and post back.

[Guest]

Make sure all the stalks are grounded.

[Strick]

I started thinking about the posts and my response, which i did quickly from my office yesterday.

Guys - I switched the right and left 'hot' wires at the rear signals, and the same with the front inside the headlight. When I then switched the turn signal to the RIGHT the left worked. So everything is grounded, all the bulbs are correct, so somewhere from the switch to the harness something is amiss.

I have replaced switches still the left will not work. Any ideas? What is the likelihood of having 2 handlebar control switches that will not operate on the left side?

I also removed the control box and jumpered the wires to see if it was the box. IF you DISconnect the box the turn signals will NOT work! In response to the first response.

HELP!

[Steve]

Did you measure the battery voltage while you were trying the signals? Either get the bike running so the voltage is up, or connect with jumper cables to a non-running car (just using the larger battery's reserve capacity) and try again.

.

[Strick]

Did you measure the battery voltage while you were trying the signals? Either get the bike running so the voltage is up, or connect with jumper cables to a non-running car (just using the larger battery's reserve capacity) and try again.

Brand new battery and bike was running yesterday. The battery also charges fine. I have put 300 miles on the bike with much starting of the engine. The charging system is stellar.

The left turn signals work when controlled by the right side of the handlebar control unit.

[gaz]

turn signal problem

Hi there,
I had a problem with my turn signals recently, the left signal would come on but would not flash and the right signal would not come on.I took off both signal lens and found that the bulb holder itself was loose and causing it to ground.A simple rubber washer to hold the bulb steady done the job.After two months still working.

[KEITH KRAUSE]

The turn signal control units on the '78/'79 1000's are known to fail. Sounds like a bad TSCU to me. They're sensitive to vibration. If you do replace it I suggest mounting it with an inch of quality foam between it and the battery casing.
A new unit is very expensive. Last I looked they were approx' $300-$350. Used can be had for much less, especially if the seller doesn't realise how much they go for new. Some just look at it as a "little black box" and let them go cheap.
The factory manual states how to test them but I don't know the procedure. There's no over the counter-test that I know of if you buy a used one.
There's info around here about by-passing the box and it takes a bar switch from the 750 model and some changes to the wiring. It then operates as a fully manual system. Some go that route.
If you decide to stay stock and a used one doesn't help, I have 3 NOS units if you're interested for a fraction of the dealer cost.

[almarconi]

Here's a thought..have you tried cleaning the handle bar switch?