Chrysler Repair: Jeep Grand Cherokee - Water ingress in cabin, jeep grand cherokee, water ingress

Question
Hi
We've a Jeep Grand Cherokee which earlier on this year suffered from water ingress, trhoughout the cabin causing ECU/PCB elecs failures.  It was 'repaired' at the same dealership from which it was purchased, although they could never actually identify the cause.  The exact same thing happened again two weeks ago causing further PCB failure to gear box module.  Do you know if this problem would be caused by the evap drain/tray or condenser being blocked or could there be another source?
Thanks very much for your time, I will be sure to rate you

Answer
Hi Lisa,
I don't claim expertise on the Jeep line, but a blockage of the tray under the dash will cause water on the floor mats there. The drain is usually a small short hose on the firewall at the centerline of the body near the place where it joins the floor. You would need to get under the vehicle to look for the stub of hose, then insert a stiff wire into the lumen of the hose to clear the blockage. If that is not the answer, please ask Kevin as he works at a Jeep dealer and would have access to service bulletins that cover unusual problems as they come to light. I am sure though that an overflow from the tray would cause the sort of issues that you have experienced. More likely would be a leak around the windshield wherein the water might fall on the body control module/fuse box under the dash and short that out. The engine controller is in the engine compartment and is not as likely to be damaged by water in the cabin.
Roland
PS Thanks for the rating/nomination if you feel it is warranted.