I SAW THIS POST FROM CFENTON AND I HAD THE SAME MISSING PLUGS. YOU CAN DO A FORUM SEARCH, TYPE IN "CAB FUMES" FOR THE REST OF THE THREAD. GOOD STUFF!
Cab Fumes - Dealer Solution Proposal
I experianced cab fumes when external HVAC is on. I also lacked plugs in the frame rails, taped instead from factory. At my first oil change (free from dealer!) I pointed out the missing frame rail plugs. The dealer ordered them and installed them - no charge.
I followed the discussion threads on fumes and absent plugs in the HVAC cowling and am guessing they may be related to absent plugs in the frame rails. If they ran out of one, they may have run out of both during assembly. The frame rails are externally apparent by looking underneath, the cowling requires disassembly to determine if present or not.
Here is what I did. I took my truck in on the transmission cooling line recall and explained to the service techician that I though the cowling plugs could be missing. I told him that I wanted them to remove the cowling and check for the plugs. If the plugs were there, I would pay the dealer the cost of removal and replacement. If the plugs were missing, then it is Chrysler's fault and they pay the dealer. The dealer/technician agreed.
The plugs were missing. They ordered plugs and will install them - Chrysler picks up the bill.
I had asked for the cowling parts description from their parts department. I combined that the pictures from:
http://www.rounsevell.com/blowby.pdf . Both helped the technician, by demonstrating the part was supposed to be there according to assembly diagrams, and demonstrated pictorially where they were absent.
I will post results after the plugs are put in. I am interested in polling how many trucks, missing frame rail plugs, experiance cab fumes.