My F250 won't trigger some traffic lights to turn green
 

Anyone else observe this? There are at least two intersections near my house that will not trigger, even after I back up then pull forward again multiple times.

I know the traffic light sensors work fine because any other vehicle I'm in will trigger it immediately. What's the problem here? Aluminum?

I can say for sure, it has nothing to do with the aluminum sheet metal.

If steel was necessary to trigger the sensor (which it isn't), your "aluminum" truck has 2x the steel of a small "steel" car.

It could very well be the aluminum body. Some lights use an inductive sensing loop in the pavement. Aluminum doesn't distort the e field as well as steel would.

Well let's hear it, what do you think triggers it?

As the previous poster said, they are usually an inductive loop. They will respond to any conductor that enters the field. Aluminum actually conducts better than steel and will be detected just fine. Most bicycles have enough metal to trip them.

Perhaps it's a small loop (you can usually see them) and your high and wide truck is straddling the sensor enough to not trip it. Could you try driving 1' to the right or left and report back?

These trucks are also much higher off the ground than small cars, and that may have an effect as well.

I remember reading somewhere in the past that guys with big tires and jacked up trucks would sometimes hang a steel weight off the front bumper so it would be low enough to trigger the light. Might check some of the 4WD forums for more info.

Yep. I have a JK that has trouble tripping lights. Height has a lot to do with it.


http://i154.photobucket.com/albums/s...psd26af66b.jpg


Sam

It's not the truck. Could be any number of factors such as time of day and programming. Could be the loop detector is faulty in which case the signal will then go into a default timing mode where the other movements have priority. Call the City or whoever owns the signal and tell them there maybe an issue and any Public Works department worth their salt will check it out.

Now I know what these are for, strictly function

https://cimg3.ibsrv.net/gimg/www.for...6a6e9d8e63.jpg
;)

It absolutely has something to do with my truck.

As I previously stated, these are lights right by my house that I pass multiple times daily. The light will trigger immediately when I approach it in any other vehicle. I can also watch vehicles trigger it consistently from the front door of my condo. I've watched thousands of cars trigger that light and never seen anyone idle at a red light there more than 10 seconds.My truck is the only one I've observed to not trigger it.

You bet. I'll try it and report back. Thanks for the idea.

You're just missing the field. Drive a little offset and you'll probably hit it, you might be able to rev your engine and set it off with the EM field from your alternators. I was able to do that at a local light like clockworks.

My sport bike pretty much never sets off inductive loops. Always sets off the lazer/lidar ones tho. I just wait the required 30 seconds and then run the light. Love that CA law.

If I am missing the field, why does this phenomena occur with apparently only my truck?