I have an auto repair shop in Maple Ridge and ran into a similar problem. Changed the vehicle battery in my PT and lost all use of the power locks SWITCHES INSIDE AND KEY FOB.Tried dam near every thing. Called chrysler and they figured the body control computer lost its memory. Said they would reprogramm it for $30.00. Well that did not work so$150.00 later they claimed I needed a new alarm module($300.00) The module was ordered and the next day while goig to pick it up every thing was back to normal. Obviously the computer lost its memory and had to RE LEARN. For some reason this took 2 weeks of driving as I dont drive far to and from my shop, has been fine for 3months now. How long ago did you have the belt done as this may be a similar problem and may take some miles to RE LEARN.......DEBO
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2001 PT Cruiser Limited Auto w/ full load 90k
, K&N , Borla SS single exh, Progress fr & rear lowering springs