Sunday, December 27, 2009

Fixing a Charging System Issue on a 1999 Ford Taurus...

My parents own, free and clear, a 1999 Ford Taurus sedan that has been in the family nearly seven years. It had about 70,000 when my sister had it and it now has close to 150,000 miles and still running strong. This is the 3.0 liter, overhead valve engine, non-flex fueled. It really hasn't needed much done to it in the time they've owned it, but one thing had finally come to fruition last week.

My dad called up, the battery light was on. This is the symbol that the charging system is out of whack and you should probably take the car in for service. Running a vehicle with a non-functioning charging system makes the battery work harder, causes the engine to misfire and will eventually damage it, along with your exhaust system. As an added bonus, it can cause the catalysts in said system to overheat because raw gasoline is being introduced into same, causing damage to the involved parts up to and including a fire.

Mom and dad parked the car and went in to check it out Christmas Eve. I pulled the battery and charged it, because the alternator (I thought this to be suspect) is not designed to charge the battery, it's mainly there to maintain a charge to run the electrical things, including the ignition, radio, power windows, heater, air-conditioner and in some vehicles even the power steering system is electrical.
Once the battery was found to be good and I looked at the belt, I noticed a chip on the power steering pump pulley next to the alternator. This can fray a belt to the point of failure, but an inspection of the belt showed that to be fine.

What delayed the project was the lack of a serpentine belt tool. Tauruses and in fact many front wheel drive cars have precious little space for tools in front of the motor to release the tensioner. After getting one, I used the 15 mm crows foot adapter on the tool to unlock it. As the belt is really tight even when it's released, you'll need to pack your patience when trying to slip it off the alternator pulley. Another wise thing to do is make a sketch of the belt and the pulleys before you take it off and do it in good light. I replaced this belt when it was dark outside and it was a pain in the neck.

Once the belt was off, I elected to remove the alternator first. First take off the negative battery cable, then remove the clipped in connectors (there are two) from the exciter terminals. The battery terminal is next with a 10mm wrench. The two mounting bolts use a 14mm and 15mm socket wrench, but keep in mind that the one in front only needs to slide out part way as the coolant tank is in the way of removing it completely. I used a medium-sized pry bar to carefully pry the alternator out of its mounts and set it aside. To make putting the new one in easier, I gently tapped the spacer in the forward part of the alternator mount with a ball pein hammer toward the passenger side. Gently is the watchword as you can break off the mounting ear if you get too medieval with it. This would mean replacing the entire mount or having the old one welded (the latter never a good idea as the alignment will likely be off and the alternator will eat up belts forevermore.

In part two, I'll tell you how to replace that pulley and get this back in working order. Wouldn't miss it.

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