Headlight/fog light interaction

[mu2bdriver]

Greetings,

This afternoon I noticed that my right headlight was out when it was used on low beam - the high beam worked. I replaced the light and ops tested good...until I noticed that my fog lights, both of them, didn't work. When I pressed the console button the green light lit up but not light from the actual fog lights. I usually drive with them on all the time. I didn't notice if they were faulty before I did the headlight. I checked the fuse and it was intact, checked the light connector and it felt tight. Could both of them have gone out simultaneously or within a reasonable time and i just didn't know it or is there some common connection that I should check before buying new bulbs.

It's a 2000 Explorer XLT and this headlight is the first one I've replaced and I drive it at nighttime @75%.

Thanks in advance.

 

[Joe Dirt]

It is possible that whatever blew the headlight (if it was a surge or whatever) also blew the fogs. I've had that happen before...

 

[albi1cnobi1]

This may sound a little silly, but did you check the fogs in low beam or high. They turn off on high beam.

 

[mu2bdriver]

Yes, I checked the fogs with the headlights on low. And on high but not expecting anything from it. At least I was right 50% of the time...

This may sound a little silly, but did you check the fogs in low beam or high. They turn off on high beam.

 

[mu2bdriver]

Is there any way I could check the headlamps before I spent some money on new ones to make sure they were the culprit? The headlight lamp that I replaced looked fine when I removed it. Not that the fog light headlamps are big $, but I want to cover all my bases before I put any money into trying to solve a problem...
Thanks again guys!

It is possible that whatever blew the headlight (if it was a surge or whatever) also blew the fogs. I've had that happen before...

 

[snoranger]

If the only thing thats new is the 1 headlight bulb, unplug it. If the foglights work with the new bulb unplugged, then its the problem. I've seen it where a crossed connection in a bulb will backfeed power into the high beam circuit and not allow the fog lights to come on.

 

[mu2bdriver]

I unplugged the new headlight bulb and the fog lights still don't work. My next step is probably going to be take the fog light bulbs out and see if they have any sign of burnout and if nothing is obvious hook up a multimeter to it. Thanks for the recommendation and great thread on the Cummins.

If the only thing thats new is the 1 headlight bulb, unplug it. If the foglights work with the new bulb unplugged, then its the problem. I've seen it where a crossed connection in a bulb will backfeed power into the high beam circuit and not allow the fog lights to come on.

 

[mu2bdriver]

I didn't even need t bother with the meter. I took the fog lights out of the harness and each of the elements were blown out. I wonder how long it's been like that or if they burned out at separate times and I just didn't notice it. But at 11+ years on original bulbs I can't complain too much.

 

[Lanky]

I took the relay out that kills the fog lights in high beams and bent the tab back so I can run my fogs with high beams! Makes for great lighting!