Odor in cab

Discussion in 'GMC Truck Forum' started by Bill736, Oct 13, 2011.

  1. Bill736

    Bill736 Full Member

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    My 2000 GMC Sierra is getting a musty, foul odor inside the cab. The same thing happened to my 1989 Chevy pickup a couple of years ago. When I turned a corner, I could hear water splashing around somewhere under the dash. I think that the problem is rain water that runs into the grill in front of the windshield, and gets trapped somewhere in the ventilation system. There must be a water drain somewhere, and maybe it's getting blocked with leaves . Where do I look for a drain to unclog ?
     
  2. gmctrucks

    gmctrucks Full Member

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    On my 93 GMC truck the drain is on the outer firewall below A/C box it's just a black little tube if you can remove the hood grill do it and remove leaves from that area.
     
  3. chevychase

    chevychase Semi-Admin
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    Every chevy truck i have owned .. been quit a few has had water in the heater box. Go around curve.. stop here it slosh.
    Only way to get it out take heater box apart will drain. At wipers area/cowl there are some rubber looking plugs that is how water gets in.
     

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