04 Heritage-Signal Lights don't work (first problems in cold weather)
 

Initially, my signal lights stopped responding whenever the weather was very cold. As the sun would come out and it would warm up, they would work again.

However, eventually they stopped working altogether. This did not seem to me to be bad bulbs, but could this be the case? Also, would this be a bad fuse?

Help is much-appreciated. Thanks!

More likely a faulty flasher unit.

I would say flasher or Multi function switch ( MFS ).

You can check and see if the flash came loose in the mount, or just replace it, and see if the symptoms continue. That is cheap and easy enough to try.

MFS cleaning is cheap, but a bit time consuming to get to it, so the flasher makes more sense to try first.

Okay, thanks a lot for the tip.

Not being particularly experienced with "flashers," I did a little research to see where this was located and what it looked like before I asked you guys.

I think it is supposed to be beneath the steering column on the driver's side, and I think I've found it. Is this it?

http://img36.imageshack.us/img36/6811/flasherv.th.jpg

That is the ODB port for hooking up a code scaner or tuner to.

Your Model in 2004 ( the same as the 97-03 ) it should be under the dash by the steering column area ( think towards the gas pedal side ), it will have 2 items in a single mount.

One is the flasher, the other I think is the blower motor relay.

https://www.f150online.com/forums/me...elay-box-4.jpg

K73 is the blower motor relay, K2 should be the flasher.

Hey I really appreciate your help and the picture, but I have absolutely no idea how to interpret that. What is that diagram of exactly?

The aux relay / flasher block that you are going to find under the dash by the steering wheel column

Okay, I don't know what an aux relay/flasher block is. This is the area beneath my dash by the steering wheel column. Would this item be behind this metal plate?

[IMG]http://img228.imageshack.us/img228/8...0018hpp.th.jpg[/IMG]

By the steering column area, that is not in that picture.

I'm not sure where I should be looking, sorry.

I am still not clear on where the flasher is located. Can someone let me know?

Okay, I found the flasher and changed it. It was TOUGH to get to. My brother-in-law and I removed the panel beneath the steering wheel to be able to maneuver better. It was very well hidden...

BUT, that did not fix the signal lights. So, as per your advice, I will next take a look at the multi-function switch.

Before I do that though, let me include some more info. All of my other lights work fine, including my hazard lights. My signal lights do NOTHING when I press the right or left signal. Nothing blinks, no sound is made--nothing.

Being that the hazard lights still work, is the multifunction switch still the best next step?

Thanks so much for the help. Sorry for the confusion about the location of the flasher, but man that thing was hidden!

Is it cold enough to make them stop working ?

They went from only working when warm, to not working at all ?

All this after the flasher change

No, it's very, very warm now. Yes, initially they only had problems in cold weather, but now they do not work altogether.

And yes, the flasher has been changed and still no signal lights. Also, again, the hazard lights work perfectly. I'm stumped.

If the hazards work, then the flasher is good.
Time to look into the MFS

https://www.f150online.com/forums/me...-turn-tail.jpg
https://www.f150online.com/forums/me...-turn-tail.jpg
https://www.f150online.com/forums/me...-turn-tail.jpg

https://www.f150online.com/forums/me...al-section.jpg

https://www.f150online.com/forums/me...al-section.jpg