I can almost promise you it's the Intercooler pump. I would bother having a dealer fix that. I would just replace it myself with the Johnson Pump. It flows more and doens' cost much. You can also go to a Ford Dealer and request a pump for a Ford Lightning. They are the same bosch pump aside from the plug, which is easy to change. They cost about $80 from Ford and about $600 from Chrysler...

Do a Search for Johnson Intercooler Pump And Ford Lightning Intercooler Pump. There are how-tos on here with part numbers and such...