I have a 1997 Cadillac Deville and the headlights would turn on UNLESS the headlight switch is off and the Twilight Sentinel (TS) is off. Once the headlights are on and I pull the headlight switch the lights go off or if I turn the Twilight Sentinel on thr lights go off.

When the headlights are on (switch off & Twilight Sentinel off) the instructment panel displays "Headlights suggested".

Before I start replacing everything can someone tell me what is causing this problem?

i have a 94 eldo & the headlights would go off by their self while driving at night.
i sprayed some wd 40 into where the turn signal lever enters the steering
column. i then kept switching from hi to lo and back and forth.
all seems to be ok now hopefully.
i hope this helps . rich

i have a 94 eldo & the headlights would go off by their self while driving at night.
i sprayed some wd 40 into where the turn signal lever enters the steering
column. i then kept switching from hi to lo and back and forth.
all seems to be ok now hopefully.
i hope this helps . rich

I'll try spraying some wd 40 this week-end and let you know if it helps, thanks for the suggestion.

I'll try spraying some wd 40 this week-end and let you know if it helps, thanks for the suggestion.

WD 40 didn't help.

Problem turned out to be the HeadLight relay switch. Located under/near the fuses on the driver side under the hood.

Cost $20.00 at NAPA.