1997 Infiniti Q45 Changing The Alternator & Harness Connector

This 1997 Infiniti Q45 Came in with a battery going dead condition. I diagnosed it as a faulty alternator. I also found that during the alternator replacement that the regulator harness connector or pigtail needed to be replaced.

Replacing this alternator looks like it would be quite difficult but it really is fairly easy. The only thing that really slows the process down is having to drain some of the coolant from the engine. To do this repair, start by making sure you know the anti-theft code for the radio (if your radio has this feature and it is active) and then disconnect the battery.

The first thing to do was to drain the coolant level down. Starting with removing the cap.

The drain screw in the bottom of the radiator requires a #3 Phillips head screw driver to remove it. There probably is enough room to use a flat  blade or common screw driver. Just be careful to not damage the plastic screw. I do not like that the bottom covers are missing from this car. Notice the rusty screws on the lower radiator support. There should have been a panel there.

The coolant does not have to be fully drained. Let it drain until there is no more coolant in the cap opening and then for good measure another cup or so of coolant.

Next remove the air intake duct that runs across the top of the radiator.

With that out of the way, you can start to see the alternator a little better. There are two 10 mm headed bolts that hold the steel plate (belt shield) to the aluminum coolant housing. There are two more 10 mm bolts that hold the coolant housing to the engine. Remove these as well.

Now, two 12 mm bolts that hold the steel plate to the intake. Also two 10 mm bolts that hold the wiring harnesses in place.

Loosen and remove the top alternator mounting bolt. Then remove the steel bracket.

Loosen the nut in the center of the tensioner pulley assembly. Then loosen the adjustment bolt until the belt is loose enough to pull it from the alternator.

Loosen and remove the alternator lower bolt.

Remove the nut on the alternator output stud and disconnect the wiring harness.

Loosen the far right hand hose clamp as shown in the pictures and position the hose and housing assembly out of the way. Unclip the harness hold down above the exposed pipe in the picture below. Rock the alternator back, forth and up until the alternator is free of the blower mounting bracket. Then roll the alternator forward and out of the hole.

Reverse the procedure to install the new alternator. You will need a magnet on a stick or similar devise to hold the lower nut until it is started on the lower alternator mounting bolt.

Make sure you tighten the bolt slowly and that the nut is being held squarely or it may cross thread.

The plastic was very brittle at the regulator harness connector and the wires pulled out. I had to install a new connector to finish the job.

Rather than cut and splice the wires, I chose to remove all of the wiring from the new connector and secure the old terminals  into the new connector body. If you need one of these connectors please click here.

Finish by reassembling in the reverse order. Make sure the drain screw is closed and refill the cooling system.

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