Hello and welcome to Just Answer!

There is no external relay for the fog lights.

The fog lights are turned on by the TIPM(totally integrated power module) which is your fuse box in the engine compartment. This fuse box is a computer itself and contains a micro processor.

The fog light switch sends a signal to the instrument cluster and the instrument cluster then determines the switch position. It then buses the info to the TIPM to turn the fog lights on. The TIPM has an internal transistor that turns the lamps on.

Have you checked both bulbs?

Let me know, thanks!

Richard

The TIPM is the most common cause of this problem and the only thing you can do is replace the module if found defective.

In order to diagnose this properly a high end scan tool is needed. I can help you test the TIPM output, but that is all we can check.

The TIPM and cluster is able to store fault codes if it sees a problem with the fog light controls. This info would help determine the cause.

Would you like to test the output circuit to see if the lights will turn on from the TIPM?

Thanks,

Richard