This 2009 Saturn Aura came in with the complaint that the alternator would not charge. Originally it came in for a no crank condition that was diagnosed as a faulty PCM. The vehicle was sent to a local dealership to have the PCM replaced under warranty. The car only had just over 31,000 miles on it. The PCM was replaced and programmed and now cranks and runs but the customer was advised that the alternator was not charging properly and it would cost about $700 USD to have the alternator replaced. The customer thought this was high since he knew he could have the alternator off and back on in about 30-45 minutes. He knew that since he had already taken it off before, along with the starter and some other parts when he was trying to diagnose the no crank/run condition himself.
I advised him to make sure that the battery was fully charged and then bring the car by so I could run some quick checks on it. I saw the car as he was pulling in the lot and motioned him to a particular bay. As he pulled in I heard what sounded like the cooling fan running on very high speed. I asked him to open the hood and I checked to see if it was the fan making the noise. The fan was not on.
The noise was in the general area of the fan and the only thing that I could see in the vicinity was the starter. I lightly placed my hand on the starter and could feel that the starter was the source of the noise and very hot. Since I could reach the starter wiring from the top of the engine compartment, I reached down and disconnected the “S” terminal wire from the solenoid. The starter continued to run. I turned off the ignition and the starter stopped turning. There must be something wrong with the starter! This a lot of stuff going wrong with a car that only has 31,000 miles on it. I racked the car up and lifted it in preparation of changing the starter and this is what I saw. I immediately knew what was wrong.
A closer look finds the blue fusible link wire attached to the motor stud of the starter solenoid. The other end of that wire attaches to the alternator output stud.What I found interesting was that the starter motor was being powered by the alternator output wire after the engine was running and the alternator was charging. With the key off the starter would stop running since the alternator was also turned off. This set up allowed the starter motor to turn without the drive mechanism being engaged into the flywheel. Had the drive been engaged and the car driven the starter would have blown up internally.
Consulting with the customer we decided to replace the starter anyways. The car had been driven with the starter running a total of about an hour. That is a lot of run time for a component that is designed to function for about one minute at a time before extensive cooling down.
Anyways the new starter was installed and the wires were placed in the correct positions.
Now the starter and the alternator worked as designed. I know that the customer was ultimately to blame for incorrectly installing the wire on the wrong terminal but I have to wonder about the systemic breakdown at the dealership that allowed this vehicle to leave their facility without correctly advising the customer of the real issue.