Hot signal lights

I have a 2005 Navigator & the signal lights will work part-time when the temps. hit 100 degrees. During winter months they always work. Only when the temps hit 100 they quit working(off & on). Big Question:Why? True Spirit

I am assuming that “signal lights” means the same thing as directional signals. But, regardless, if the lights in question work sometimes, but not at other times, and if this seems to be related to ambient temperature, I would start trying to find a bad ground connection in that light’s circuit.

Although this is normally something that is a problem at low temperatures, I suppose that it could also occur at high temperatures.

The problem may be within the flasher unit. You could try swapping it out. I would assume power is being interupted when this happens.

I too would start with the flasher unit. This is basically a thermally operated relay anyway.

Thanks for the reply. The dealership doesn’t know what it is, can you believe that, HA.