No break light issues

[81 spitfire]

This weekend I decided to try and fix the tail light on my 1980 spitfire. I was able to get the running light to work, but there is no change in illumination when the lever is pulled. I hooked up a test light to the break signal wire and it would turn on and off with the use of the break lever, but I am getting no change in the illumination of the bulb when I have the wires all connected to the bulb. I have a bulb out of a trailer light with the high/low filament. Has anyone had this problem before?

Thanks

[harleysportster]

Remove the seat and inspect the wire harness. It sounds like there is a break in the wire somewhere between the handlebars and the taillight.

[JDT]

The bulb socket could be the problem also.

Grab another taillight assy and plug it in with a jumper wire to chassis ground.

If you loose the ground wire to the taillight what will happen is the lamp will actually dim when you apply the brake.

If the wire is broke like Harley suggested it will not work at all on brake application even though the taillight is working.

[81 spitfire]

I checked the wires and they are all good, I am getting power all the way to the socket on both wires. I will go out and check the ground and see if that is the problem.

Thanks

[AirborneX4Special]

Might be a brake light switch malfunction. Plastic plunger pops out when you use the brake handle.