I've got a 1992 Seville that I'm having trouble diagnosing the twilight sentinal. I've gone through all the diagnostic steps, and it says to replace the black module on the back of the headlamp switch (I forgot the technical name). I bought a used one, and still didn't fix the problem. Are these modules common to fail? What would you suggest I do next? :bonkers:

First, what is the symptom? What is it doing, or not doing, which it should be doing? Maybe I have electrical savvy enough to help.

The symptom is the twilight sentinel is not working at all. Headlights won't auto come and the delay doesn't work either. Headlights otherwise work OK. Light for the twilight sentinel comes on when you cover up the sensor, but the headlights don't come on.

I would suspect contact in or around the sensor. Even if indicator lights show the sensor to be working, there may be a connection that doesn't allow full current. Have you checked and worked over wire connections?

I am having the same issue. The twilight sentinel does not work at a all. It performs no function. Although I am capable of manually turning on the lights at at dusk I would still like to be able to see how the sentinel works. I have a 1991 and was hoping someone may give me some logical progression steps and where to find the steps. Thanks

I have an 88 Eldo with the same symptoms and the computer diagnostics say its been shorted in the switch but the manual works and if i cover the sensor the lights go on inside but not my headlamps