How to Replace the Evaporator on a BMW 325i

1. Drive your vehicle to your local A/C repair center and ask them to remove the Freon from the system. Repairing your A/C with a pressurized system can cause serious injury, and it is also against the law to release Freon into the atmosphere.
2. Drive your BMW back to your work area. Lift up the hood and locate the battery. Use a socket wrench to remove the clamp attached to the negative terminal. Pull the negative cable away from the terminal.
3. Enter the interior and use a Phillips-head screwdriver to remove the four screws that hold the instrument cluster in place. Slide the cluster out of the dash and unhook the electrical wiring from the rear. Remove the screws which are attached to the lower dash panels. Remove the panels to gain access to the evaporator core.
4. Locate the air conditioning module at the bottom of the dash. Use a socket wrench to remove the defroster ducts found above the unit. Remove the bolts that hold the evaporator core housing in place. Lift the housing away from the core and remove the core from the BMW.
5. Insert the new core and cover with the housing. Secure the housing in place with the mounting bolts. Attach the defroster ducts back above the unit. Reattach the dash panels and instrument cluster by following the removal steps in reverse.
6. Connect the negative cable back on to the battery terminal. Drive your BMW back to the A/C repair center and have your system refilled with Freon.