I have 130K -140K miles 2.7 V6. Driving to the store, check engine light has been coming on and going off intermitantly over past month, airbag light on for awhile, all of a sudden ABS light comes on, hit the brakes a couple of times and it goes off, brakes appear to be fine. Park car get out and smell somthing like a burning clutch (automatic) assume that it is in the air and not from my car. Go in store come back and smell is in passenger compartment, turn the key dash lights are on and nothing happens (fairly new battery). Open hood and can't locate smell but it is fairly strong in the passenger compartment. Back under the hood and the only place I can locate the smell is by the PCM. Tow car home, lights are still strong (it is night). Next morning the battery is completely dead and does not seem to want to take a charge. Smell is faint by the PCM, remove PCM put on bench and no smell???? Any ideas??

 

With all those lights coming on your car has obviously been having one or more issues for a while. There were probably fault codes stored in the computer(s) which could have been retreived but may now be gone.
You're going to have to find that short circuit. Start by taking things apart near where you can smell it and look for signs of a short: burned wiring, arcing tracks, whatever. If you can locate the damaged area and repair it, you may then want to charge the battery and see what else has been fried in the process. Your PCM may be gone if it had too much voltage.
If the ABS and airbag lights are still on, you will need to get the car hooked up to a proper scanner that can get in deep and get readings on those components.