I know there are some other threads about this, but I have a specific (stupid?) question --

First the background.

I'm driving a 2003 XJ8 with 65k miles. I just bought the car and love it.

I tried using my auto headlight setting when I first got my car a week or so ago -- they didn't come on, so I just used the manual setting (no big deal).

Then today I noticed in one of the other threads that there's a sensor and a knob on the back of the rearview mirror - that's for setting the sensitivity, right?

Well, tonight I tried it by turning the switch to "auto" and then turning the sensitivity setting to the left all the way but the lights did not come on (how long should I have to wait?) and then turned it all the way to the right, still no lights. So, I used the manual setting.

Ok, almost there...

Later tonight after driving about 1/2 hour with the lights on manual, I was parked with the engine running and the car in "D" when I flipped to the "auto" setting and the lights stayed on. I thought, ok now I've finally got the sensitivity thing down pat and they're going to work. Wrong! I drove about 20 minutes and stopped at a store, turned the car off with the switch in the "auto" position, the lights turned off when I turned off the ignition -- good, right? But, when I came out and turned the car on, no lights. I tried again to set the sensitivity but nothing would turn the lights on except to put the switch in the manual on position.

So, the question(s) --

1. As you sit in the car facing forward, is "more sensitive" to the left or the right?

and

2. How long should I have to wait for the lights to come on? The owner's manual says there's a slight delay but doesn't say how long.

and

3. Any suggestions for "fixing" this problem? Cleaning the sensor?

Not a big deal, like I said, I can use the lights in manual mode forever, but it would be cool have this option working.

 

A cotton bud to clean the sensor? if that doesn't fix it, it's a deeper issue, probably a wiring fault at the stalk, where the auto wire has broke away from it's solder point. I've fixed a couple this way.

The fastest way to test it is to cover the sensor with black electrical tape once cleaned and turn the ignition on, the lights should fire.

 

Thanks, I'll try cleaning it and covering it with black electrical tape.

 

I have the same issue, for sure it's a bad soldered wire. Any description of how to repair it? If I move the stalk a little up, like for the right indicators, it works.

 

Q tip?

 

Cotton bud, you mean a Q-tip?

 

A Q-tip is a brand of cotton bud or cotton swab. In the same way that a Hoover is a brand of vacuum cleaner.

 

Interesting: three comments on a four and half year old problem.

BTW: another case of never hearing what the fix was. Not sure Old Mike is still on the forum for his 308 or his S-Type. Pretty sure it was a broken solder joint (as it was in my case. Got really pissed on the interstate when this guy kept high beaming me; got off a dark side street and realized he was telling me to turn on my headlights: auto had failed. Took all three of my hands to resolder it. Third hand was surgical pliers).