My 2003 expedition suddenly began to smell like something burned inside.

hey thanks for replying, i got underneath the truck and looked at the entire exhaust up to the headers, i didnt see anything and the smell wasnt there

Okay , well at least that is ruled out! Had one in the shop today , and that's what it was . ......Was worth a shot!...Does yours have a cabin air filter? maybe something with that 'holding' a previous odor?

yea it would have been really nice if that was the solution to my problem...Yea the cabin air filter is next on my list, but unfortunately i think the problem is going to be electrical. Ill elaborate, a few months ago i noticed that the cars alarm was really faint when i pressed lock and unlock with the remote, kind of like if the battery was bad. then a few weeks after this, while driving the truck studdered, almost turning off, well i guess it did for a split second then i just went on my way. it did this again when i was backing out of my garage, this time shutting down completely. But then started right back up. I charged the battery and it seemed to take care of the stuttering because it didnt do it again. another thing the truck does is when the headlights are on and i move my windows up or down the headlights dim. Or when i turn on my headlights my radio turns off then back on. ok fast forward to this week with the burning smell. 2 days after the smell appeared i attempted to leave work and it stuttered! So today i went to autozone to get a new battery, they tested my old 1 and said that it was fine, that it held a perfect charge. I insisted and was given a new battery at a prorated price. So i went home and installed it, well to my surprise the faint alarm was still there, it barely honks...so the new battery didnt take care of the problem. So it looks like i have 2 unrelated problems, OR my truck has had an electrical short that has gotten worse and is now producing a smell. Ill also be checking the fuse box...

Is it an 'aftermarket' alarm system? , also , from your description , possibly the alternator/harness or related item? Yeah , the more story you tell , the more possibilities come up.Keep me posted , I'll do my best.

actually the Truck is 100% stock, the alarm is from the factory. Ive been researching the stuttering problem, and it seems to be an issue for some people. This is what i came up with: 1. Theres a wire that goes from the battery terminal that's notorious for rubbing on an ac line(potentially causing the smell in my truck?). 2. Fuel pump relay 3. bad fuse box. these were the common fixes for their truck stuttering. ill check 1 and 2 tomarrow.

Hope you find it! Persistence pays off.

thanks, it looks like you were right about the alternator. I had it checked out and was told that it was bad. I ordered 1 from pepboys and will pick it up when they tell me that its ready. That should take care of the stalling, faint alarm, and dimming lights(all symptoms of a bad alternator). So I researched burn smell coming from vents, and there is no mention of a short being the reason, i keep reading that it might be the evaporator drain? So that's where im at now. I tried finding the cabin air filter, but i think that this was an option from ford. So my truck doesnt have 1.

Keep at it! Thanks for the update!.

Update: I found the source of the smell and hopefully the reason for all of my electrical problems. The connection that goes from the battery to the fuse box was burning at the fuse box, quite literally. I just need to replace the fuse box, hopefully no other damage was done.

Unearthing here...Same issue and solution. 2003, replaced fuse panel. It's cold so I'm running the heat. I smell plastic burning like the old relay. It's like having your mouth washed out with soap..dial soap. You never forget the taste....well, I never forget that smell. You see?? Or Rather smell? :) Bid the fuse panel fix your issues? And do you still have this god ol' buddy?!

WHAT WAS THE CAUSE OF THE MELTED TRASH BAG SMELL IN THE EXHAUST FOR THE EXPEDITION?