Howdy,
I have a 2003 f150 5.4, and I love it. Been very reliable overall. Today something weird happened.

Got to the grocery store, turned off and removed the keys. As I got out of the truck, I noticed the stereo was still playing. Once I turned that off (which I never have to do) I heard the heater fan still going, then noticed the odometer reading --------- ? I fidgeted with the keys in every conceivable order and could not get them to turn off. Went home and the same deal. I had to unhook the battery to get everything off?

Took it to a buddy's shop and we switched the ignition switch with no change. Made an appt with an auto electric shop for next week and brought it home to park in the garage and tinker. I unhooked the battery and it sat unhooked for about 5 hours or so. Went back out to start finding relays (as a guess), plugged in the battery and everything is working normal.?????

Is there something (maybe a relay) that screws up specifically when warm? Maybe one that runs the dash stuff (ie heater fan/stereo).

Any advice would be sweet!!

Scott

 

Does this normally sit outside?? Have you recently had rain or snow? or drove in rain and or snow?

It might be that your windshield or the sunroof ( if so equipped), might be leaking. And the water is migrating to the GEM module causing "strange" things to happen with your electric devices. The GEM module is just above the "E" brake , back side of the fuse panel.

 

Leaky Windshield Syndrome - a collection of various symptoms that appear when the GEM and/or fusebox get water in there.

Been raining or having snow melt prior to symptoms?

 

projectSHO89 and enriched are right. Check the GEM and your windshield.

 

I have looked around in there a fair bit, and it is bone dry? No leaks that I can see at all?

 

When you changed the ignition switch, did you have to pull the steering wheel? If you didn't. all you changed was the key. The ignition switch is on the steering column under the dash. There is a link that is a known fail on the F150. The link is moved by the key and works the ignition switch.

This is NOT the ignition switch


THIS IS AN IGNITION SWITCH:

 

We changed the switch (lower pic) and it didn't change anything so we replaced the old one and took it back. We didn't have to pull the steering wheel, just a bunch of plastic.

 

Exactly. The key is the Ignition Lockset, the switch is behind the lockset.

 

Well it turned out to be a faulty relay. I took it to a reputable shop and they figured it out and fixed it. Everything was fine for about 2-3 weeks, then....

Tried to start truck and battery was dead for no obvious reason. Put my bump starter on and dome light flashed like hazzards, heard a relay clicking on/off/on/off/etc. Flipped the key on then off and it stopped. Charged the battery, and when I turned the key....nothing...at all. Tapped on the interior fuse/relay box and had a blip of everything normal and then gone again.

I removed my GEM and fusebox (kind of a beotch) and GEM looks great. I didn't rip the fusebox open, but it's a little "dusty" where the two big plugs go in the back. (If you've done this, you know what I'm talking about because they also are a beotch to remove).

Called ford and they wanted 450 for just the fusebox so opted to gamble on ebay with a "refurbished". Also bought a new GEM. Have to wait a week but anyone think I'm way off in this spending frenzy? Do the symptoms (basically no power to anything....at all) match anyone's experience? Hoping the relay issue from a few weeks ago was just a symptom of what I'm dealing with now?

Thanks for any insights.

 

I doubt it. Wrong symptoms. Most likely, they swapped the relay and it just happened to start working so they thought the fixed it.

You never addressed the earlier questions regarding rain or snow melt.

 

dup post...ignore

 

Well I live in Washington State so we've always got rain and have been having snow melt too. Everything seems pretty dry up in there. I peeped back flooring back and it was a little humid under there, but not super wet.

I popped open the GEM and there is no visible issues with that.

Thanks for your help!

 

I second (third?) the Leaky Windshield. Same thing happened to mine. Turn the key to start it, lights would start flashing on and off, doors locking and unlocking. I was certain a ghost was going to come out the vents, but nothing yet...
Ended up being the fusebox that had gotten wet and was shorting out. Because I'm a miser, I actually pulled it apart and cleaned it then siliconed it (although I still replaced the windshield later on anyway).
Haven't had any problems since.