Lots of defective logic. Relays and thermostat are up high and will not be affected by running over something. Water pump won't be damaged either. When you start throwing a bunch of parts at it without a proper diagnosis, you introduce a lot of new variables. BMRFIXIT suggested fan wiring. That makes the most sense. If he is right, it will not overheat on the highway when the wind is blowing through the radiator. If it does overheat, coolant is not circulating. Check for a crushed or pinched lower radiator hose, or a serpentine belt knocked off the pulleys. With the belt off, you won't have power steering either.
The codes you read are 12 and 55. 12 just means the ignition switch was turned off. 55 is the end of the message. Both of these are normal.
Wednesday, May 27th, 2009 AT 9:36 PM