Turn signals quit when brake is applied

[Tommize]

Turn signal quits when brake is applied. Two mechanics replaced ground. Didn’t help.

[Swagonmaster]

Has anything been done recently to the bike? Bulbs replaced or anything?

[thrasherg]

Which ground? 99% of the time this is a ground issue, there is the ground connection from the battery negative terminal to the main bike frame, but then there are other ground connections, between the rear top box lights to the bike frame, and the front bike lights to the frame. You don’t say if it’s the front lights, the back lights or all the indicator lights that stop working, but I would think you still have a very high chance that it’s a bad earth.
If you have a length of wire, I would strongly suggest connecting one end of the wire to the battery negative terminal, then start the indicators, apply the brakes, so the indicators stop working, and then whilst keeping the brakes applied touch the other end of your wire to the ground side of the bulb (you will need to remove the orange lens to get access to the bulb) if when you connect the wire, the bulbs light up then you have proven it’s an earth issue, if they don’t light up then you have another issue. But the test takes 5 minutes to try and will prove if it’s an earth issue or not.

Gary

[Tommize]

Bulbs were changed, ground was added, trailer light module and pigtail installed. I rode about 200 Miles it was fine, then it started again.

[DaveO430]

You didn't mention but does it do that only with the trailer connected? Has it had a conversion to make the turn signals also work as brake lights?

[Viking]

Bulbs were changed, ground was added, trailer light module and pigtail installed. I rode about 200 Miles it was fine, then it started again.

I have had those trailer light modules be bad from brand new. We bought three of them for three GL1800s several years ago, and only one was good. The other two were replaced at no charge without any argument at all about them being electronic modules. Obviously, it is common to get one that is not functioning correctly. Kinda the luck of the draw. This is what I would be suspecting.