Ram 1500 models yes. Heavy duty models, I think will fit as well.
Gas engine it is in the tank, on the fuel pump. Diesel engine it is on the driver side of the block.
The PCM is also the trans computer. It is located dead center under the hood.
The fuel pressure regulator is part of the fuel pump module, in the tank.
Clogged radiator, also it could be a bad thermostat, or fan cluth all 3 have failed on my 2002 ram1500