Replacing the alternator on a Cadillac Catera is not one of the easier repairs to make in your front or back yard. It can be done, but allow some time for it as well as patience. If you have a bad back, you might consider letting the professionals do it, but if you're not scared by the disclaimer thus far, grab your tools and let's get started.
Park the Catera on a paved flat surface. Apply the parking brake and release the hood latch. Using the wrenches, screwdrivers, or ratchet and sockets to your desire (unless otherwise specified) remove the following components. Remove and isolate the negative terminal from the battery post.
Remove the intake air resonator located on the passenger side to gain access to the alternator beneath it.
Loosen the lug nuts on the passenger front tire using the breaker bar and a 1/2-inch drive socket. Lift the passenger side front quarter of the Catera and place a jack stand under the front frame rail just high enough to get the wheel off. Remove the lug nuts and wheel.
Remove the wheel-well bolts and remove the wheel-well insert. By doing this, you'll gain access to assist you in the removal of the alternator. You might find it easier to work from the top of the motor where you'll have more leverage, but if you need to access a certain bolt or find it easier to disconnect some parts from the alternator from down below, this will give you another option.
Place the box end 15-mm wrench onto the tensioner pulley bolt head and turn clockwise. Remove the belt from the water pump pulley, but do not unravel the belt from all of the pulleys.
Remove the coolant heater duct (if applicable) and remove the alternator cooling duct.
Remove the electrical connectors from the alternator. That consists of two plugs and a nut holding the wires to a stud on the alternator. This is where dropping down might be a little easier than trying to reach everything from up above.
Remove the alternator bolts (2) then remove the alternator. This will take some wiggling, wrangling nd manipulating to extract the alternator from the engine compartment and again, you might find it easier to extract from the exposed wheel well area.
Install the new alternator and reverse the process. When it comes time to reattach the belt, again turn the 15-mm wrench clockwise and make sure the belt is lined up properly on the pulleys with all the ribs in the belts where they belong. Any belt rib not on the pulley accurately will make getting it back in place properly impossible. You may have to check down in the wheel-well area to the lower pulleys.
Replace the wheel-well insert and bolts. Replace the wheel and lug nuts and tighten the lug nuts flush to the hub. Lower the Catera and tighten the lug nuts with an adjustable torque wrench set at 100 foot pounds and a 1/2-inch drive socket.
Replace intake air resonator if you haven't yet and lastly replace the negative battery terminal to the battery post. Test start the Catera and make sure everything is working as it should.
