Got in the STR to go home during bright daylight knowing the auto-on headlights will remain on regardless of the abundant light. I switched on the little parking light bulbs for the 40 minute ride home. As the daylight waned I switched her to auto-on...wa la! The headlights remained off then switched on as I passed through dark wooded sections of the parkway, switching auto-off as I drove back into well sun lit road. What happened?

 

Sounds to me like you accidentally initiated a system lighting reset procedure. I've had the same thing occur on ours a couple of times back during the winter months. The headlights would occasionally come on in broad daylight and stay on for awhile. I tried cleaning the windshield sensor to no avail. One day when the headlights came on again, I turned on both front and rear foglights, then moved the switch from auto-on (where my wife always keeps it) to off, left it there for perhaps a minute, then moved it back to auto-on. Voila - the headlights stayed off until dusk, and the issue hasn't popped up again. Don't know if this is an actual published reset or if I just got lucky, but if it happens again I'll do the same thing. If the same results occur, then I'll know I'm onto something....

 

uh, am I missing something here? With the HL on auto they are off in bright sunlight, go under the over pass for a uturn where it dark and they come on. Pull out back into sunllight and they shut off again. Sounds light normal operation to me

 

Brutal, I was having the issue where: while on auto-on the headlights remained on. Now possibly through some re-set process the feature operates normally.

 

bfsgross: Has your dusk sensor continued to work since you originally posted? I have the smae problem, and occasionally they will work correctly after I jiggle the switch, or turn on the fog lights. But after a day or so they just stay on all the time again. I'm thinking maybe the switch is just bad.

 

Sorry. Zachster, since that June/2010 post the auto headlights haven't functioned properly. I use the headlights manually. The independent Jag tech is checking with his friend, a Jag corp. tech. troubleshooter for a solution. I'm guessing the underlying cause is the photo-voltaic sensor on the dashboard is toasted. I'll keep ya posted and the same please.

 

The sensor is in the rear view mirror if you look at it from the front throught the windshield you should be able to see it.

 

bsfgross: Thanks -- I think I will try replacing the switch, and will let you know if that solves the problem. I had the opportunity to replace the sensor when I replaced the plastic dash fascia in March (it was cracked by the hot Arizona sun when I got the car), but didn't think to do it at the time...

Vance: The mirror gizmo has sensors for the mirror itself (the dimming feature), and for the compass -- at least on the 2000, the mirror is a self-contained Donnelly unit that has no other interaction with the car's functions. That may have changed with later models.

 

Zachster, my dashboard fascia is also cracked from its original Florida and Virginia homes (now resides in NY). The heat probably denatures the covering of the sensor, causing it to lose its transparency. This fools it into thinking it's dark all the time. I'd go with replacing the sensor before the switch? Regardless, please let me know how it went.

 

BFS,

Any idea on price for the sensor. Mine also stop functioning some time ago

 

Chris, not a clue on price. I'm guessing approx. same as a sensor for A/C? I'm waiting for the independent Jag tech to get the Jag Corp. tech troubleshooter to the car to inspect it. Let us know what you find on your side.

 

My 2000 has two sensors on the dash -- I think the domed one is for the lights and is also the solar sensor for the A/C. The other seems to be for the alarm system. When I removed the fascia, I saw that both sensors are on a single wire loom, so if you have this same settup you can probably expect to have to replace both as a single part. I think later models only had a single sensor.

 

Thanks for the info zachter.

 

Following up on this problem, before I could get around to replacing the headlamp switch, I had to replace my energy robbing starter due to a hard starting condition. For no apparent reason, right after replacing it, my dusk sensing suddenly works flawlessly! The headlights are also brighter, so I have a theory that maybe the dusk sensor simply doesn't work if the electrical system doesn't have the correct full voltage (which, in my case, was remedied with the new positive connection point on the new starter).

 

Wow. Good fix (however it came about).

 

Wow zachster. You lucked-out dude. My STR starts fine and all so I don't think a new starter is in the cards. I'm still waiting for the Jag tech to scan my car for codes and other issues. Thanks for the update though.

 

Mine was acually starting fine about 80% of the time, but on occasion (when the engine was warm) it would need three tries. Then eventually four. Then one morning it just wouldn't start even though the engine was cold and it was cranking. I assumed the problem was something other than the starter, but my mechanic explained that the starter was drawing too much power so that it wasn't turning the engine quite strongly enough and actually causing flooding as a result -- the circuit was also affected in that it wasn't temporarily cutting off things like lights and radio while cranking. The power draw seemed constant, even after starting, and was affecting other things, the alternator working overtime to put out insufficient voltage (making that slight squeeling sound), and the battery therefore not getting quite enough juice, dim headlights, etc... The whole time I thought it was the alternator that was the problem but it now appears to be fine.

 

I dunno? I understand a "dragging" starter lowering voltage to electrical system...but to cause a low amp sensor to malfunction? Maybe? I thought it could be the battery disconnected during starter install: Causing a hard re-set that re-set the headlight sensor, etc.?

 

Can't say as I know. I've disconnected the battery for other reasons prior to this, with no effect on the sensor. The fact that the lights are noticeably brighter maybe means that the whole circuit that the sensor was on suffered. Electronics are not my strong point, so my theory may just be bunk!

 

Nah, yer probably on the right track. I'm itching to git to the bottom of the auto headlight issue and feel strongly the sensor is toasted from high heat (she was originally a southern car) in my STR's case.