PontiacBonnevilleClub.com

Dumb question. .. where is the twilight sentinel photocell located on my dashboard? Is it the dome in the middle? Secondly, here's my problem. When I start the car up in the dark the lights will NOT come on automatically. I've turned the settings from max to minimum if that helps. In the end I have to pull out the light switch. My 1999 Pontiac Bonneville works perfectly fine.

you either have the shaded dome or a button like sensor near the drivers side windscreen. so even when you put it in drive the lights are off? be sure the parking brake is off as that will prevent lights on.

I have a dome in the middle and on the drivers side it looks like a pushpin but I thought that was for just holding down the dashboard piece. Brake line tested and off. I guess I don't understand the dome or the other item.

If you have Electronic Climate Control, you will likely have two sensors. One will look like a button in the defroster vent area usually, which is the for the twilight sentinel. The dome could be be a solar gain sensor. Solar gain is one of the factors the ECC weighs when determining output temperature.

I don't have electronic climate control. Any ideas from there.

its prob ably this one............https://www.amazon.com/Genuine-GM-12450 ... B000QIVXTI

https://www.amazon.com/dp/B007QB78VA/re ... B000C9DHA4

Your original twilight sentinel solar sensor is a button (flat) sensor. I actually recently sold my 92 SSEi and am now selling my collection of spare/extra parts I had obtained for it (just in case), and am selling that particular sensor. If you are just interested in seeing it, or even interested in purchasing a replacement, here is a link to the item I have on eBay. If you check my items for sale on eBay, most all involved the 92-99 Bonneville's, and in particular, the 92-95 SSEi's.

https://www.ebay.com/itm/302668906146

For reference, the domed solar sensor above the dash, near the windshield, is for the auto climate control system, and looks like this:

https://www.ebay.com/itm/302668909118

It's a flat button, slightly smaller in diameter than a dime, located about three inches inboard from the A pillar on the driver's side. It's easy to remove; just pry it out with the tip of a pocket knife. The one on my '95 Bonneville never worked right, even after I grafted in a headlight switch from a '98 model. I swapped in a couple of sensors off of junkyard cars and it made no difference. Eventually, I just gave up and operated the headlights as a manual system. I finally proved to myself that the problem wasn't the sensor by swapping it into a '97 Cadillac DeVille I had at the time. That car had major issues with the automatic headlight system, which stayed in daytime mode, so I was driving around at night with the daytime running lights and no dash lights. I had sort of remedied that issue by simply removing the sensor and operating the lights manually, but the original sensor out of the Bonneville put it back to working perfectly.

The headlight switch for a twilight sentinel equipped vehicle is different than a conventional switch (vehicle without twilight sentinel). Quite often, those switches fail. Your issue is most likely was with the switch itself. I have 3 of these switches for sale in eBay, if they are of interest to you (they were for my 1992 Bonneville SSEi. Used a few, but the 3 I have left (after selling the SSEi) were never tested, so I can't guarantee their condition. But they are available if someone wants them.