Wjb727

The automatic headlights just quit working. If I switch them to on they work fine. It also appears as if the dash panel lights are out as well, although I have only checked in the daytime. Is there a specific fuse or relay that controls the automatic portion of the headlights?

DennisMik

iTrader: (2)

Check fuse # 1, top row of fuses, left end.

There is a control unit for this feature under the dash, located next to the OBD port, right side. Fuse # 1 powers this control unit that gets input from a light sensor in the dash on the left side of the defroster vent. The control unit or the sensor could have gone bad.

Wjb727

Are you speaking of the fuse box on the left side of the steering column or is there another fuse box on the right side of the steering column. I'll apologize in advance for not being a maintainer so I don't understand the acronym, OBD.

I'll be checking in the morning.

Mikel81

obd is on board diagnostic port. It is by your left knee under the dash when sitting in the driver seat.

Wjb727

Thank you, sir. I looked at the a/t fuse on the top left of the fuse panel. That hasn't burned out but I don't know about the sensor going bad. Is there a good way to check that? Don't want to pull out every fuse but I can do that just to check if one has gone bad.
The auto lights came on when I turned on the car to warm up when I was clearing snow off the windshield but I saw them go out (and not knowing why, I was wondering if it were a fuse or something else). As long as the lights work normally, it isn't that big of a deal; however, if I don't have the dashboard lights, I am a bit more concerned.

DennisMik

iTrader: (2)

The auto light system works both ways. It uses a light sensor to turn the lights on when the outside light is low as the sun sets or maybe in a parking garage. The sensor will also turn the lights off when the outside light level is bright enough. Your recent post sounds like the auto light system is working OK. For future diagnosing, if something works intermittently, the fuse is not the problem. Fuses are 100% good or 100% bad.

As to the dash panel lights, there is a brightness control switch that could have been accidentally turned down. It is on the dash to the right of the drivers side air vent outlet.

Wjb727

In reverse order, the dash panel lights were full bright. I keep them all the way up and they were in that same position this am when I checked the rheostat.Agreed fuses are 100%. I was describing again what was going on when the lights went out. It wasn't an intermittent problem. I could have been clearer in the that statement.


This afternoon I had to go into DC and parked in the parking garage, staying about an hour. On the way out I checked the auto lights to see if they happened to work. Yea! They came back on. My initial impression is that the sensor has a problem. I say that because I have run the car with running lights on auto for a dozen years and have never seen the lights out day or night and the clock light always ran dim, even with the dimmer rheostat full high.


Good thing is the lights seem to be doing their thing so I'm a happy camper. Bad thing is I never remember the sensor turning off the lights in bright daylight.
Who knows but thanks much for the help and descriptions.

DennisMik

iTrader: (2)

Great! the headlight part is straightened out.

Now, are you having a problem with the dash lights? The fuse for the dash lights is under the hood next to the battery. The cover has the fuse labeled TAIL LAMP. This fuse also powers the tail lights. If the tail lights work, this fuse is OK.

Wjb727

Everything is working well now. I suspect there may have been some build up around the fuse maybe. Resetting that seemed to cure all. I reread the owners manual for the auto lights. Apparently it does turn lights off when they aren't necessary. I did not recall my headlights ever being off but until this past year my car has been garaged so the headlights were always on when I checked them.


Thanks for the details.

gapboi210

ummmmmm that's what makes AUTO headlights AUTO....they turn off and on AUTOMATICALLY as needed. If they just stayed on that would be ON